Truly my best appraisals have came back when we didn't cheap out on the reno.
As Tim said, make it look above average to the appraiser. My best BRRRR's ever have been when we went the extra step i.e paint the exterior, go all out on the kitchen and baths, nice landscaping etc..
The best one I completed was located in Concord (sub city of Charlotte) in October of 21
Purchase price 94,000
Reno 47,442
Appraised Value 205,000 (we originally estimated a 175k ARV)
On this one, we carefully picked our finishes which needed up making it the nicest one on the block. To get a free BRRRR in the Charlotte, NC market is tough, much less getting one you can cash out on.
This doesn't mean you have to spend tons of extra money. Instead of a tub insert, do a tile surround (the price difference is a couple hundred bucks.) Instead of painting all the cabinets white, do the lowers a different color to create variety. Keep it simple, i'm not saying paint your lowers pink. A light sage green or navy blue will do. Pick nicer finishes - get the $300 v.s the $150 vanity. Wooden shutters help too.