If I'm in a rush to water my plants and just guesstimate how much they will take I dump that into the pot and take off. Lots runs thru into the tray and I might leave it overnight and if there is still water left in the morning then I'll get it out. A good method is use a small towel. just roll it up and lay it in the tray then wring it out into an empty tray for disposal. If humidity is low then wring it out on the floor or tray and let it evaporate. Preferably I'll empty the trays an hour after watering. If the plant itself was really dry it will pull up as much water as it needs in that time and the media will be totally saturated too.
That being said I have intimate knowledge of how much water each of my various pots needs when they are in need of watering. My current Hindu Kush flowering plant in a 7gal pot takes 7-8L of water every 4 - 5 days. I judge the actual need by lifting the pot. 4 days after a good water it's light as a feather compared to freshly watered. You can figure 1/4 the volume of the pot to saturate it when it's dry enough to need watering with soilless peat or coco based media tho coco need much more frequent watering than peat based like the ProMix HP I use. Soak/dry/soak . . .
A good method is to get a bunch of those Tiki Torch wicks and put maybe 4 in a 5gal pot. Then have the pots sitting on anything that holds them an inch or so off the tray so you can just leave extra in the tray for the media to suck it up over a day or so or bottom feed your plants and let it wick up to keep the media moist all the time. It's a very old method of watering plants and evaporation from the trays will keep RH up where needed but conversely will keep RH up where it's not needed as well. Those platforms made to elevate fabric pots should work great but DIY is a lot cheaper and there's likely all sorts of stuff locally available you could use for that a lot cheaper.
So many ways to skin the watering cat. lol
