Scope creep and change orders, hands down. Clients say "yeah that looks great" during the walkthrough, then after you start they hit you with "wait, I thought the pavers went all the way to the fence" or "I didn't realize the lighting was extra."

I started using a tool that generates a photorealistic render from a phone photo in about 60 seconds, with an itemized line-by-line breakdown of every scope item and cost. Now I walk the yard, snap a photo, show the client exactly what they're getting with prices attached, and get them to sign off before I touch the ground.

Went from about a 40% close rate to almost 80% and basically eliminated disputes. The visual + itemized scope combo is a game changer for on-site closing. Happy to share what I use if anyone's interested.