stencilface
High upon a hillside
I think thats fine for a first go. I have nicked my horse in the past - did he shy away the next time I came at him with the clippers and stay at the back of his box? Nope
A tiny cut is not exactly going to bother most horses.
I find full clips much easier, as no lines to do really! I will be doing a neck and belly/chaser clip on mine this year though, as he's not in much work, so I look forward to a fun time. I normally clip off half his face too, but one year I clipped his whole face, bar his muzzle - he looked like homer simpson - it was hilarious! Did he care? Nope - luckily he wasn't going out in public for a few weeks

Chalk lines are good for the first few times, but confidence is a major thing, now you have done it once, I'm am sure all the little niggles from this time will go, you need to do long sweeping lines to get a good finish, once you start clipping off little bits at a time, it all goes downhil - and quickly!
I find full clips much easier, as no lines to do really! I will be doing a neck and belly/chaser clip on mine this year though, as he's not in much work, so I look forward to a fun time. I normally clip off half his face too, but one year I clipped his whole face, bar his muzzle - he looked like homer simpson - it was hilarious! Did he care? Nope - luckily he wasn't going out in public for a few weeks
Chalk lines are good for the first few times, but confidence is a major thing, now you have done it once, I'm am sure all the little niggles from this time will go, you need to do long sweeping lines to get a good finish, once you start clipping off little bits at a time, it all goes downhil - and quickly!