The most creditor-proof way to structure an inheritor trust, also known as a beneficiary-controlled trust, is to have co-trustees. You can make your child, who is the beneficiary, an investment trustee, meaning they are in charge of managing the investments and overseeing how the assets are invested and managed to ensure they appreciate over time.
You can then appoint a distribution trustee. In this structure, your child, as the beneficiary, has control over everything except the distribution decisions. The distribution trustee is the one who decides when and how distributions are made.
What makes this option different from the HEMS (Health, Education, Maintenance, and Support) standard is that with this second option, all distributions are purely discretionary. They can be made for any reason, with no constraints whatsoever on these types of distributions. As a result, a creditor cannot make any claims against these discretionary distributions.