You can buy plant pot drip trays in lots of sizes.

I have a 40 foot concrete patio with 35 pots on it. They are all on either wheels or some sort of stand. I would love to have a patio makeover. Stains come when damp, woodlice and dirt and hard water residues make a ring under the pot. Plants don't like to stand in water either, so no saucers for me. Plant out your pots with a layer of water retaining gel crystals near the roots. If you can see exposed roots, from watering, pop a handful of new potting soil in over a sprinkle of gel crystals. Water so that it does not run out the bottom of the pot. You will soon get the knack. We are on a meter so water that runs out the pot bottom is wasted. Enjoy your new patio Slater.....I am jealous.

Plants in containers outdoors should not be sitting in drip trays. Indeed they should be raised up on feet so that they are not in contact with the patio. Himself relaid our patio last year and we have small troughs and pots on it. Once in a while I move them and sweep the area water does not stain the paving stones.

When I use a drip tray (not often) I put the tray up on pieces of bricks to allow airflow under the tray, and more pieces between the tray and the pot to keep the plant from sitting in water. The alternative is to use a bulb baster to suck out all the water from the tray 15 minutes after watering, but sometimes that takes too much time!