Here's my modest, little pond
Small, back yard, in-ground garden ponds are great for birds, cats, racoons (it does take some patience to put up with the results of their visits). The sound of falling water distracts you from traffic noise.
At the moment, I’m setting rocks along barely perceived changes in the back yard’s elevation. The pond is at the lowest point — maybe 8 inches below the high point, diagonally across the yard. To a critical eye, it is a fantasy. At a glance though, the outlined water course above and some ruble below give the pond a context however contrived.
What you absolutely have to have for a pond: a fence and a gate because ponds are what they call an attractive nuisance and a drowning danger for very little kids, some mosquito fish to eat the mosquito larvae because ponds are perfect breeding grounds for mosquitoes. You will probably want a small pump too.
How to make a pond:
A backyard pond is a broad, shallow hole ringed by a 4 to 6 inch wide and 3 inch deep shelf full of gravel. The hole is lined with heavy plastic.
To make a pond dig a broad hole with a shallow ledge all around. I like marsh plants, so the other end of my pond is very shallow and full of mud. Some gravel leads from the mud into the pond proper for the smaller birds to walk onto for bathing. I’m pretending that a ring of heavy stones kind of keeps the mud in the shallow end.
Buy enough pond liner to fit in the hole and ledge with an inch left over above ground. It’s tricky to measure because of the shape of the sides. You need the ledge because the edge of the pond is full of gravel. Dirt won’t work because the water would wick out of the pond like wax up a candle wick or water up a paper towel. It’s called capillary action. The amount of water lost is surprising. Gravel hides the pond liner well. Trim the plastic just below the gravel so you can’t see it.
I cut my ledge pretty wide and set bricks in a little concrete as a rim. You can decide whether to have the gravel inside the rim or, like mine, outside the rim.
The liner is fairly heavy-duty plastic and needed because racoons like to dig. Unplug your pump at night. Raccoons love to mess with pumps. Thread a wire through the pump’s tube and attach it to the pump. Again, raccoons love to fiddle with the pump. I’ve found tubes that they’ve taken from the back yard all the way around to the front yard. I’ve looked out in the middle of the night to find mother raccoon lounging in the pond while her young frolic in the yard. She looked like she was at a spa.