I am new to cake decorating and don't have a lot of experience with attaching dried decorations to fresh fondant. I've used RI and melted chocolate, but you can sometimes see the glue glob. Anyway, for my most recent cake I decided to make some gum glue using water and tylose (a recipe I found here on CC). It made just a small quantity and decided to try something . . . I poured it into a medical syringe, the kind with a removable plunger and a screw cap on the end (like this http://www.amazon.com/Syringe-60cc-Luer-Lock-Sterile/dp/B000FN897I/ref=sr_1_4?ie=UTF8&qid=1366564321&sr=8-4&keywords=medical+syringe. It was easy to apply a drop of glue directly to my dried decoration and stick it to my cake. And since I used only a tiny bit on my project I can cap the syringe and save it for my next project. This might be old news to some of you pros, but I was quite excited at my "discovery".
The recipe I followed was 2 Tbsp warm water and 1/4 tsp tylose. Sprinkle tylose over water and let sit overnight.