Originally Posted by Snowmom:
I don't think it's unreasonable to expect parents to "help" their child be more independent with self help skills by setting them up for success.... i.e.; proper clothing 
If it were me, I'd either type up a memo, write on my communication board or newsletter addressing the issue.
Dear Parents:
I really need your help. As a group, we've been working on self-help skills. This skill builds their confidence by becoming more independent & self reliant. In order to accomplish this, they need clothing that is easy to manage themselves, which is where I need your help. If you could help your child choose daily clothing that is easy to put on/off, it would really help your child as well as the entire group. Please refrain from any complicated clothing such as buttons, tight clothing or tied shoes.
Thanks!
I have done this in the past and will do it again in the future if need be. I always approach it as being beneficial for the child because xyz therefore please ensure that the items sent in are ones that can be easily put on/off by your child.