Re: Effective small pond fishing
You're getting good advice with these posts. I thumbs up just about everything said. Bass and bluegill ponds are mt bread and butter. so I'll chip in my $.02
To reiterate: Floating line should be fine. No need to get carried away with leaders. I frequently use regular monofilament in various lengths. Start with a bit of 20 or 30 pound test, then lengths of smaller diameter. 6lb or 4lb test on the end threads through most eyes of trout and panfish flies. You could always add a length of actual tippet for the small stuff if needed.
Here's my own thoughts:
1.) There might be a good chance to nail some carp. They're often in ponds, including grass carp as they often stock them to cut down on weeds in urban ponds. There's a good excuse to buy another rod as carp are big game. You might want some actual leaders to make a gentle presentation.
2.) I've found it helpful to learn the roll cast and tower casts for these waters. I often find myself fishing off the dam and that high embankment makes backcasts a challenge. These casts overcome that problem.
3.) Flies: a lot of ponds have their own list of insects and other critters. Pay attention to what you see, and maybe tie/buy accordingly. Standard nymphs and buggers are great everywhere. One that stands out for me is a flie that suggests a small bluegill or green sunfish. Bass feed on them here. You also mention koi. I wouldn't be surprised if you were successful with orange streamers.
Edit: In answering your question on retrieves, I vary mine. There's long been a tradition among bass fisherman of casting a frog imitation or popper on the surface, letting the rings dissipate, and then give it a twitch. Let the rings dissipate, and give it another twitch. Repeat. This certainly works, but I don't let myself get too glued to it as it's ulitmately up to the fish.
The twitch doesnt have to be much, even just a slight movement. You'll find the hits will happen just after you twitch it in most cases, often right after the initial cast and the first twitch. I think the initial splat attracts the fish's attention, and the twitch provokes a reaction strike, especially with bass. (If you really want some fun, throw that thing over a bed of spawning bluegills and watch them bat it around defending the nests.)
I vary retrieves subsurface as well, fast, slow, creeping, erratic, consistent, whatever. The most underrated I find is creeping things along the bottom superslow.