Someone already said it, but I think that one of the most important
things is to not "punish" if there's an accident or if the child won't go
while on the potty chair. Making it stressful like that would probably
set the training back and not help at all, I'd think.

I never once made a big deal out of it and it just happened when my
daughter was ready. She was 2 and there were only ever just one or
two bed wettings during the whole process.