The cheapest way to establish a trust or assign a trustee?

[oreoxoreo]

Only got my pension pot and my house, almost divorced and 2 small children. If I die I want to split it 50/50 between my DC and assign someone (probably my ex, their father).
Don't have an extra £1000+ to establish trust... what is the easiest way to get about?

Make a will. The will creates the trust.

Ah, really? I have a will, but didn't know it creates a trust. I might need to amend it. Thank you.