So, psychic can be useful with serene grace, since its chance of lowering the opponent's SpD is higher, and it has a higher base power. Signal beam can also confuse pokemon, is decent coverage, and has a higher base power, if you want a better chance, use water pulse, for Psychic STAB is best from Psychic, not confusion.
Jirachi Stall would do better with cosmic power instead of thunder, thunder misses often and I see no point in it :P
If you want an electric type move, use thunderbolt, although it has less power and paralysis chance, it has more accuracy and reliability. Only use thunder if you have rain support.
Flash cannon is generally more reliable than doom desire, has more PP, and can lower SpD. you can have Recycle for chesto berry+rest or stall aguav berry.
Trick can be a good setup. Steath rocks helps utility. Wish is good.
There are a lot of other ways, and we haven't gotten to natures, IV's, EV's, and Items yet.
Look at what team you want to put it in, and then decide which role it'll play
Ex: Stall, Wall-Breaker, Sweeper, Cleaner, Utility, Setup Sweeper, Wall, etc.
Basically, best for what?