At which stage of your skincare routine do you apply base prep products?

Lately, I've become interested in prep products used before makeup, like Yeonjak or Jung Saem Mool Base Prep!

I'm curious if these products are used as the final step of the skincare routine after applying cream, or if I should finish with a prep product instead of cream and start immediately with sunscreen or base makeup!

commonly Skincare → Prep → Sunscreen → Makeup Should I use them in that order?

For those of you who use prep products well, I'm curious about the order you usually apply them in, and also about a good routine for using them without any stickiness!