Massive thing at the moment is co production with parents.
Ideally, parents would be at meetings where APDR targets are set and agree or contribute to them – but this is a workload issue for many teachers / SENDCOs who may have high numbers of SEND pupils and parents are often only involved in EHCP annual reviews, in reality.
Parents should also co produce things like SEN policy / information report.
For me, all senior leaders should be leaders of SEND (just as all teachers should be teachers of SEND) as otherwise the SENDCO is bashing her head against a brick wall when it comes to discussing SEND priorities at SLT meetings. Upskilling senior colleagues who may have little experience or knowledge of current SEND thinking is huge!