Great advise. I was a GC for over 30 yrs. As the saying goes… Good work is not cheap, cheap work is not good. Pros stay busy.I was in the flooring/tile installation biz for 40 yrs. Unfortunately heart surgery in 2019 ended that. I built many custom showers & always left my customers with a big smile. Always used old school methods. If you do the tearout/cleanup yourself ,then have your plumber relocate the controls & drain you will save $$$. When interviewing tile men ask lots of questions (about procedures & leak prevention) even though every job is different preparation is basically the same & is very important! Be sure they use a moisture barrier/anti fracture membrane product. Know in advance what you want - shelves,seat,recess,soap dish,grab bars,etc. Add ons or surprises are good excuses to charge more after they’ve started. Have them make you a complete material list & have it on the job when started. Check progress daily , if you see something ask questions. Most people who know what they’re doing don’t mind answering questions or explaining procedures. I always gave customers options & let them make decisions never tell them to do it like it’s theirs, always act like you know what you want & what’s going on even if you don’t. There’s a lot of half assed workers around that produce half asset results out there. Take time to try to find somebody competent it makes a difference in the end.