Here are some tips for shooting in city limits, and keeping on the down-low.
1) Quiet target (avoid plastic bag targets since they can be quite loud, I prefer foam blocks or softer 3D like a Rhinehart). I have tested a bunch find the quietest targets. Believe it or not, the most silent target is a burlap sack filled with old clothes packed loosely. Problem is arrows drooping though.
2) Use a generous backstop (neighbors will see you are responble as well - may minimize their concern). A larger size net can help as well. I have seen arrows really bounce up on occasion; rare, but it does happen.
3) Shoot a quiet bow. I put 2 sets of silencers on my recurve (can only hear some noise as string comes off tab, then a light thud as hits target). Heavier arrows may help noise as well.
4) Avoid shooting when other will see. Most people have a routine (avoid lunch time if they come home for lunch, etc.). Likewise, weekends when kids are outside is a bad shooting time.
5) Limit number of arrows shot. I work off my back deck and find that shooting to simulate hunting (1 arrow every 30-45 min) has greatly improved accuracy. Also, you can do close-range work on form inside. If you bow is tuned, it will shoot with minimal wobble at 10-12 yds. A round 36-48" grass matt target should catch even the worst shot (almost) at close range.
6) Block the neighbor's view. Plant cover trees (Magnolia are very good) and stagger them. This also blocks the neighbor's view. If you are quiet, and they can't see you there will be little chance of them reporting you.
7) If neighbors come outside, be respectful and don't shoot.
8) Be very discreet. Don't look like a full-blown archery range in teh backyard. Ideas: keep a block, straw matt, or 3D target in a storage shed, and take out for practice (then put the target up). I also have plans for a 6 ft wide x 8" high arrow curtain that will totally block the neighbor's view across the 1acre thick woodlot. Now that Fall is here, the leaf cover will thin out. After each session, I will simply unhang the curtain.
I shoot into about an acre of thick woods (with home on other side). And I have 2 elderly neighbors on each side who don't come out much. I tried to pick the safest and most conceiled position for my target.
You can tell I put some thought into this. I just want to do what I can to avoid losing the pleasure of shooting a few, frequently in the backyard. Hope this helps someone else do the same.