Here's one I just made. Took all of 1 minute or
so.to make. Just a bottle, twist ties, and a knife. These also work well to catch vinegar flies in your house. Just put in some fruit, beer, or vinegar and soapy water/soap to break the surface tension. Add a low-temp light under it, wrap the light and all the bottle but the top, with a towel, and you have a nifty nighttime insect catcher for getting bait or just to get rid of those Multicolored Asian Lady Beetles from inside your house during the winter. Bury it upright with only the funnel part showing and it makes a good fall trap for crawling insects. For this last usage, use different baits to attract specific insects you want to use as fishing bait, great for beetles and crickets:
http://mississippientomologicalmuseum.org.msstate.edu/collecting.preparation.methods/Baiting.htm 
