More than once it happened to me that I got stuck in a derivation. Formulating the question on MSE with nicely formatted TeX and describing step by step how far I got then helped me to get forward and answer the question myself.
For me it would be great to post the question nevertheless and answer it right away, if only for later references. But once I know the answer, the question often looks trivial and it feels I should rather delete it.
Note that my question in particular pertains to proofs or proof-like derivations. Does it make sense to formulate the first part of the derivation as a question and the second part that I came up with ans an answer?
Any suggestions or similar experiences: keep+answer or delete?