I changed my hours to 8-4 by appointment and I put window perf on the windows and door so nobody can see in - BEST THING I EVER DID.
I typically do not lock my door when I'm here but when I do, it's because I'm behind and I'm getting interrupted too much. A couple times a month I will lock the door, turn the music on, silence my phone and email and get working for a couple hours. Interruptions are terrible, they say it can take 23 minutes to get back on task. If I come in on a Saturday or Sunday I also lock the door. I've never had any commercial work come from a weekend, only people looking for a sticker or just being nosey.