Techies
Techies is pretty different from most other heroes, with no direct combat skills and crappy stats. Laning against him can be easy or a pain depending on how you handle it. The first thing you have to watch out for is suicide, which can easily land Techies a first blood or even a double kill. Check if Techies has boots first, a decent indicator as to whether he is going suicide first (not 100% though). Be wary if he suddenly runs at you and always keep your distance. Also make sure you know if his lane partner (solo techies is really dumb) has a disable to hold you still while techies blows you up. Keep track of the runes if you can in case he gets a haste or invis.
The other annoying part of dealing with Techies is the mines. This used to be easily countered with wards but now that they are nerfed wards aren't really a good solution. Keep track of techies and note if hes been missing for a while. Be careful before crossing common areas like your secret shop, the runes, and ramps. Remember flying heroes (Visage, THD, Viper, Harbinger) won't set off land mines but they will take damage if other units set them off. A gem or a Necronomicon are both great counters to Techies, rendering him pretty useless if you are there. Necronomicon and other summons, as well as illusions can also scout lanes or areas ahead of you to check for mines.
A pusher techies will go for your tower with land mines, which will take it down pretty easily. In order to do this he is going to have to run into the fray and plant a mine next to your tower. When he is running in nail him with a stun if you can and pound on him, this will give him second thoughts about trying it again.
Mana Burners
The two main mana burners are Nerubian Assassin (mana burn as a spell) and Antimage (mana break as an orb). A few other heroes have ways to reduce your mana but none as threatening as these two. Both turn your mana against you, making it difficult to stay in lane, much less harass back.
There are two ways to deal with it - one focuses on survival, the other on harassing back. If your hero is not a strong lane controller you probably will have to use the survival method. If you can pull it off harassing back is optimal.
Anyway, on to the survival method. The idea here is to keep your mana as low as possible and play defensive. With no mana it is harder for mana burners to hurt you (Antimage has pitiful base damage and NA is left with Impale which costs much more mana than Mana Burn). Avoid unnecessary mana regen and blow your mana on spells as soon as you can. Of course this makes it difficult to harass or get kills...and it can become an issue once Antimage gets his ultimate.
The other method is simple. Blow all of your mana immediately on the mana burner. Let them know that they whacked a hornet's nest. If you are successful you will intimidate the mana burner and he or she will keep their distance...if not keep at it, but switch to the survival method if you are putting yourself at risk.
Silencer with Curse of the Silent
This little combination is very annoying for the first few levels. What you have to realize here is Silencer is passing up on something in order to get Curse, stats and Last Word (or Glaive I guess, which would just be flat out hilarious). This means Silencer is slow, has low hp, and only a DoT for defense which you dispel by harassing him. What you need to do is either harass/kill him immediately so he is out of the picture for a bit (similar to strategy for mana burners above) or conserve your casts for when he casts it on you. When you are forced to cast always hit Silencer, make sure he knows every time he curses you he is going to get a nuke to the face so he stops doing it.
Try to conserve mana and have enough ready in case he curses you, or at least have a tango ready. Don't worry after a few levels Curse won't be nearly as dangerous and Silencer will have traded a lot of mid game usefulness for early game control.
Axe
Axe can be a real pain for melee heroes. Battle Hunger is very annoying at lower levels of play, while Helix (and Call) based builds are effective at higher levels. To deal with hunger all you need to do is perfect your last hitting and denying and its really quite laughable. Usually Axe will drop a hunger on you between creep waves then charge you the next wave to keep you off the creeps. Battle hunger doesn't really do that much damage unless you take it for the whole duration, so stay calm and focus on last hitting, don't try to engage axe but don't run away either, pop a tango if you have to. Remember the cut off point for Culling Blade, if you fall below that you need to hide from Axe or go heal.
Now, the real threat is a non battlehunger axe. He is going to charge you at the creep wave and get off a lot of counter helix's from all of your creeps attacking him. If you attack him back you are going to be taking an obnoxious amount of damage, back off and harass with nukes or switch lanes with a ranged hero with better lane control, ranged nukers destroy Axe. Remember, Axe wants you to attack him, a smart Axe will be setup to take hits and Call makes him pretty invulnerable with the armor boost. Once you get in Culling range he will finish you.
Pudge
Pudge can be pretty scary to lane against if you know what he can do. Generally he isn't to bad if you always keep in mind that he is around. Watch his position carefully and always keep a creep or two between you and him. If you can't see him then call missing and assume he is trying to hook you. Keep a creep between yourself and likely hooking spots (the woods, or across the river, or up ledges). If you are caught and he is running along with you rotting, juke him, once you get out of rot's slow its not to hard to get away. Just remember, don't run in a straight line because this makes you easy to hook.
If you can hold Pudge down early and keep him from farming it is difficult for him to make a come back. Always remember to call him missing if he leaves your lane - theres nothing your ally can do if he doesn't know Pudge is coming and is hooked and dismembered before he can take action.
Lord of Avernus
Described by some as "the best melee lane controller" a good Avernus can be a real pain even for orb walkers. His shield gives him a nice set of options for harassing and protecting himself or allies. As usual, its nice if you can get ahead of him in the early levels while his shield is still weak. It is imperative that you manage to get ahead before level 6 because once he gets his ult you are going to have a very difficult time finishing him.
Avernus will probably shield himself then charge you, in this case you should retreat to your tower. If he chases you into tower range you should try to slow or disable him, or just fight. At this point you are going to take damage when the tower blows the shield so you might as well get in as many hits as possible while you have the tower helping you. If you can take off a good chunk of Avernus' hp he hasn't really accomplished anything, which is good. This strategy starts to fall apart once Avernus hits level 6 because he will use his ult to shield himself while running back from the tower.
If Avernus is having trouble with charging you he might start to shield creeps who are taking lots of hits to try to catch you in the explosion before you can back off. This is usually a sign that he feels threatened, just back out of shield range when one of your creeps is taking all of the hits and be especially careful at your tower. If you can keep up with him and avoid enough shield explosions you can hold the upper hand, making him not so threatening, just difficult to kill. If you find yourself unable to run from him just get a scroll of tp, he has no stuns.
Keeper of the Light
Keeper of the Light is known for the havoc he wreaks on a lane during the early game. The key to laning against him is avoiding Illuminate and not being intimidated by him. Illuminate delivers a powerful blast in the direction he is facing, but it has a long charge time and leaves his back and sides completely open. KotL is very fragile, you can send him packing with only a little bit of harassing. It is important to send him back as soon as you can because the Illuminates are not going to stop - with Chakra his mana is virtually unlimited. Remember, if you stun KotL or interrupt his channeling in anyway the Illuminate will immediately go off (albeit weaker), instead of being canceled so be cautious.
A skilled Keeper of the Light won't be hitting you head on, he will be hiding in the forest and blasting you with Illuminates that you can't even see coming. So if you notice he is missing, be wary and stay away from the creeps and any forest area where he might be hiding. The hit range for Illuminate is actually much wider than the animation so make sure you are well clear.
It isn't too dangerous if this guy farms up (it is difficult to stop) unless he stacks another teammate (against the rules in many circles). The main issue here is if he totally shuts down your farming and leveling, then you will have a problem.
Secret Paths and Juking