Using low minions to trade is a pretty effective way of harassing/poking with the least possible counter-attack from the enemy laner, and this goes for all three lanes.
If you're finding that you're not making this work it could be for a couple of reasons:
First, it might not be working because you've seen a low minion and chosen to attack them. Because the minion was low, but not actually low enough to die, they auto'd you once, then last hit the CS. It's important to make sure that them autoing you is actually going to cost them the CS you're looking at denying them.
Second, if they've chosen to attack you, they might actually have missed that farm. In this case they've 100% made the wrong decision unless they've really chunked you for a sizable portion of your HP. If you just take 1-2 autos to deny them a farm, and trade an auto or 2 in return, then they made the mistake and you just need to repeat this.
The important thing about that second point is that you be landing your CS. This is the biggest thing that people struggle with; if you're missing CS that you don't need to miss then you're negating any good you've done by focusing so hard on denying theirs.
If you need any extra help or have any other questions you're welcome to add me in game and we can chat or practice. I've spent a lot of my time in the pre-season helping low/mid elo players get ready for the ranked season, so hit me up if you like.