Well, I do tend to get a lot of first bloods by hiding up the enemy hill middle and suicide low armored mid players like invoker etc. Boots + Suicide.
It's somewhat risky but the first blood payoff is great for a hero like techies, you have your boots already and almost got your soul ring by then.
Even if you do fail the kill enemy, your mid is still at an advantage because of the damage you did. They either gonna run home or use a lot of consumables.
The other thing is just knowing the mechanics, if have enough remotest at one tower, just move on to another lane (You gain xp from kill anywhere on the map). Some of the best spots to catch out an enemy is the first tier tower so you would want to keep those up as long as possible and not allow the enemy to gain momentum via their gold.
You might not be able to do three lanes, but it's very possible to keep 2 lanes fully intact for a very long time.
This one might be controversial, but with techies you'd actually want the lane pushed, if creeps are near their tower they can't see you where your planting mines.