Well I decided to complete the Unown dex and whilst I was doing it, a Shiny 'O' Unown popped up! That's my newest shiny yet, although I do want to chain some more Pokémon.
In my chaining party I usually have:
1) Togekiss (Knows moves with 32PP , means I don't have to use ethers or visit the pokécenter that often)
2) Scizor (named 'Falsy') this is my False Swiper, knows some attacking moves as well. I swap this for Togekiss when the chain reaches 40.
3) Arceus, my HM slave (I got this in a trade, instead of releasing it I thought I'd better use it)
4) Usually some sort of Syncer, as I usually plan to use the Shinys I've caught in competitive battling, this is cruicial. 99% of the time this Pokémon is an Abra.
5) If it's a steel or electric type, then I will use either my Elekid or my Nosepass.
Good look with your hunting!