When hunting parks I just hunt and mind my own business. I don't make a mess, I don't leave holes and I pick up other peoples litter. I only hunt the oldest parks and I am at them often enough that the maintenance guys have all seen me, know I am not breaking any rules, and they just give me a friendly wave when they pass by. Earlier this past summer, I did have one young girl who was emptying the trash barrels come up to me and tell me I couldn't "dig in the park". I politely told her that I knew the city park rules and that what I was doing was perfectly within the scope of the park regulations. I offered to show her the regs, but she just said she was going to call her boss and have him come talk to me. I told her I would welcome the conversation with him. I detected at that park for another two hours and he never showed up.
In terms of curbstrips, I hunt them fairly often but I usually try to let the adjacent homeowner know I am there, what I am doing and that I will leave it as I found it. I also ask if there is a sprinkler system in the strip, just to make sure they know I am being careful. I have had a couple of people ask me not to and I respected their ask, but more often than not, the conversations turn into granted yard permissions.
I don't try to hide my activities because I am doing nothing wrong. I don't hunt at night because I hunt in the older parts of town that have some questionable characters milling about and situational awareness is necessary. Darkness does not help in that regard.
I can only say that if you know the rules where you are hunting and stay within their boundaries, you should be bold in your pursuits of the treasure you seek.