We get a reasonable number of questions along the line of "What filter was used for this photograph?", where "filter" is used to mean Instagram-style digital filter rather than a physical-type polarizing, neutral density etc filter. Two recent examples:
The trouble with these questions is that good photos aren't made by selecting a filter in Instagram, but instead by thinking about light, composition and all that difficult stuff. One possibility would be to come up with a canonical type question we can redirect this type of question to, but I can't quite see how to write that canonical question. We could just keep closing them as "unclear", but that doesn't really seem to help the posters learn.