The bute I prefer is powdered apple flavor. Last year or so our vet has ordered maple flavor, and I haven't found one yet that will take it. Huge pain. The apple flavored powder I could put on their feed and everyone I used it on liked it.
The way we give pill form bute is crush it, and put it in a cut off hose. Then, put hose in their mouth and blow it in. This is my least favorite way to administer, but at least you know they are getting a full dose at once. It's not a way I could deal with for very long, as it's a pain.
If I don't get bute paste for some reason, I crush the pills to a powder and dissolve in a liquid/paste of some sort to top a small amount of grain. Either apple sauce, or a tiny bit of molasses dissolved in hot water and poured over a little grain. I usually don't like adding molasses to anything, but they usually lick it right up without snubbing.
I get the liquid form from my vet - ours is Strawberry flavored. Not a huge fan of the paste, pills or powdered forms. I like to just squirt it down the backs of their throats and be done with it.
Be careful if you (or anyone at your barn) are ever going to show that anything you use to administer the bute is not a daily use thing because it will stick around and depending on the association you (or other people) show with your (or their) horse could test positive months down the road.