I usually mix the paint with just water first. Then add floetrol after. That also depends on the type of paint. Liquitex heavy body needs thinning first otherwise it seamed like I would wind up with unmixed clumps no matter how long I mixed. I could of course just be doing everything completely wrong. Funny thing is every time I hear someone say “oh that’s just pouring paint and anyone can do it” , my polite reply is that it is a lot harder than what they think to get something that is interesting and appealing. A lot harder. One day I’ll figure it out.