What order to put things on your face?

[Dilbertian]

Steroid ointment/cream, moisturiser and sunscreen. I can never remember in which order to apply them.

Treatments / serums, moisturiser, spf in that order

You should leave 30 minutes between steriod and moisturiser.

Thanks!

The steroid is an as-needed treatment. If I need to use it a few hours after I have applied moisturiser or sunscreen, do I have to cleanse the skin before applying the steroid? Most sunscreens I use definitely leave a residue, whereas others seem to disappear.