I have searched for this and cannot find the thread. Can anyone help me?

What is the best way to stick fondant to fondant? I am especially worried about the sides.

Thank you so much!!!

water. Yep, it's that simple. Just use a little, you don't want the fondant too wet. HTH

I just brush the back with water and a small paintbrush.

Is as simple as that!...Water..not too much..You can use extract too!

paintbrush and water

I have also heard of vodka or clear vanilla.

I have used water and clear vanilla.
HTH.

you can also buy/make sugar glue but water works fine, depends on how much you need it to stick.

I use the glue if I am making figures but if just sticking a pattern onto the cake where not much weight is involved then I just use water

here is Aine2's video on how to make the glue...

Adding to what citrus said the water is ok for the cake. When you are working with gumpaste and more complicated stuff is better to have a glue with some consistency.
Edna

Alcohol based extracts are good as the alcohol evaporates quicker than water. Adhesive is made with 1 TBSP water to 1/4 tsp fondant or gumpaste. However, as mentioned water works too.

For really heavy stuff, I have used piping gel. But I'm with everyone else, water is the way to go most of the time.

My cake instructor taught us water with fondant in it. How I do it is I warm up the water. I take pices of fondant and use my ball tool to flatten/thin out. ThenI put it in the water. I found the fondant desolves faster that way than when it is in balls or clumps. For heavy stuff, piping gel is great.

i was taught to use piping gel but u have to be really neat with it. it can make a sticky mess but it holds well!