^
good thing you know that by now :D

I could um well.. but what luther said is actually the perfect thing to do.
If you get 100 cs in 8,5minutes .. even against bots that's already freaking strong. 107 minions spawned at minute 10.

Some common tips:

1. Melee Minions usually die after 2 towerhit's + 1 AA so getting these isn't even that hard.
2. Caster Minion usually die after 1 towerhit + 2 AA's or you got enough AD then 1 AA will be enough... so while the tower is hitting the Melee Minions you got time to hit those 1 time.
Doesn't always work due to minions and stuff but that's how it's done.

I could... but then koksei will come here and laugh at my face; which is totally justified.

Get a burning hot iron ready, and every time you miss a minion, Brand yourself. You'll improve in no time :3

I wuv you kat <3

lol.. I hate you arcana

always work on improving it but if you find you really cannot get csing down try champ roles that dont require as much cs such as tank/support/jungle (only way to lose last hit in junlge is for someone to walk up and steal it).

Lol you say you have annie down... Rank game 47 cs, you played by yourself rumble 48 cs.... In rank no less >.< I don't think you have csing down on annie kat :P

Play Video
Essential techniques.

After you understand that, the rest is just pure practice.

Listen to music that's your preference with a continued beat or rhythm. As a AD player for my team, every tournament or Ranked game, I put on a nice song with a nice beat like RNB, Rock, Rap, Trance, etc and that gets my mentality to CS in a little rhythm and it's just a lot easier to do it successfully, missing very little!

Ofc you have to practice CS'ing and it gradually improves the more games you play as long as you know you made a mistake and are willing to accept it and learn to trying to learn to avoid situations like that in the future ever again. Examples of gradually learning how to CS like melee creeps can take two tower shot and 1 AA for a successful CS and caster creeps can take one tower shot and a AA for a successful CS. Just play and you'll improve :)

edit: adding some examples. They probably won't be your preferred type of songs but this is the kind of music that gets me pumped and ready to CS!

Town by Dumbfoundead - http://www.youtube.com/watch?v=R_DyA1kNAHI

Witchcraft by Pendulum - http://www.youtube.com/watch?v=AooMCiV2eb4

editedit: god I feel like a nerd needing to get "pumped up" to play a game xD

I play both of them, especially Irelia. It's so fun just dashing around minions.

Play Nasus or Irelia. Melee Csing is more "dangerous" and should help you with the practise of Csing safely.

Also: Last Hitting.

Don't practice too much in customs.
Application of CS-ing in normals is VERY important.

When playing a custom game add a bot or just get pretend there's an enemy there, because if you only practice in customs, you will overextend to get a cs and get harassed x9000