EDIT: Thanks to Toshabi for pointing out the flaws. I needed to tell you guys which ELO range this works in. All of those games were played in 1500-1950 ELO range. Read toshabi's rage below, look at the results, and then judge for yourself.

Would you like to try something for me?

I can reward you.

I can give you a first blood and a double buff NP at right around 3:15 in the game.

Next time you're blue team top lane, consider this:

Push the hell out of that first wave. Cut backwards, and into river bush at 3:10. From there, if you weren't followed (and I hardly ever am), cut over to their red. If their jungler is there, wait for the precise moment to initiate the rapage. If he is not, wait about 5-10 more seconds, then head back to lane and accept the lost XP.

Of course, don't try this if they are a jungler that starts red, or if they are spotted heading to your own team's red. 99% of the time though, you'll end up with a first blood, a double buff, and one PISSED OFF lane opponent.

(Teemo works exceptionally well for this, just go to their red a bit early and waste a few seconds camoed directly under red (they cant target you as easily). ENJOY.

Have a nice day, let me know how it worked.