I think as a buyer, you deserve to tell a maker exactly what you want. The ones I've dealt with, and I'm convinced most in general, want to know exactly what you want. They may offer opinions, options, reasons they feel some of what you want won't be for the best - in general they may & should make it a 2 way street in educating themselves as to what you want & educating you in what's the best way to get it.
After numerous custom cue experiences, there are some things I know I want & some spec's I know I want to stay very close to. Joint type, weight, balance point, taper characteristics, shaft diameter, joint diameter, butt diameter - all are real important to the overall relationship between the player & the cue.
Your cuemaker, if he's worth fooling with, WANTS you to be happy with the result. And it's up to you to be responsible about who you chose. The characteristics - playability & aestethics - that you want should be matched to what a cue maker has exhibited proficiency in providing. If you take a flyer by giving a young maker a chance to "stretch out" and do what he's never tackled before, you may be disappointed.
You need to take as much ownership of your intentions as possible so that you give yourself AND the cuemaker every opportunity to be successful - you both have a vested interest in that success.