Any ideas for DYI drip trays?
Depends on how utilitarian you wish to get; a piece of aluminum gutter with a "leaf preventer" on top would work. Pretty cheap.
Or any type of wire grate that was long enough and narrow enough to fit in, say, a drywall mud pan such as something like these.
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I usually put a folded piece of paper towel on my drip tray just for the drips so I don't have to clean it out as often. If I have friends over, I'll take it off and expose the drip tray, but it keeps it suprisingly clean as just the few drops get soaked into the paper towel quite readily.