I've done it! I've managed to get DD to take her inhaler without having to pin her down and her screaming!
I put In The Night Garden on TV, sat her on my lap facing the TV, gave her the first puff and counted to 10 very quietly in her ear. Removed the spacer for a short while. Repeated a million times (or so it felt). No tears, no screaming and, most importantly, no breath holding which has been her latest trick.
She then took the spacer from me (I removed the inhaler, naturally) and carried on putting it to her face and breathing in.
She's 19 months old and has had the inhaler since May! I thought we'd never get to this point (although to be fair she hasn't had it often in the past few months, only when she has a cold with wheezing.)