Have posted occasionally with niggles about dd's teacher not really grasping her difficulties probably because she isn't typically autistic, she's statemented but very able (HT said outstanding but he does gush a bit 
) and no behavioural problems and no real social issues either.
Anyway I have tried hard to maintain a good relationship, tried to offer suggestions rather than criticism and given the teacher pointers on what is likely to work for dd.
I think at times the teacher has found me a PITA quite probably because I do want to have more input than the majority of parents. I want to see what's being achieved with the IEP and like to tweak things if I think there is a better way.
Anyway the teacher has taken my interference in mostly good grace even if she didn't think some of my suggestions were needed (because dd causes no problems in class)
At dd's last IEP meeting I wrote the targets,the methods and the outcomes because I didn't like the teacher's suggestions and I think the teacher thought she'd humour me.
It has been a turning point, my IEP is getting results, dd is happier and less anxious and as a result is progressing faster than ever and her teacher admitted that she had been sceptical at the time but she was glad that I had been right. Now the teacher is fully on board I think the sky's the limit tbh.
I have always liked the teacher and thought she was a good teacher now I think she may just be a brilliant one for dd.