If I hit a clue that simply reads 'wan', I treat it like a neat little puzzle instead of a mystery. First I look for the definition: in most cryptics the definition sits at either the beginning or the end, so 'wan' is very likely the definition meaning 'pale', 'ashy', 'pallid' or 'sallow'. That immediately gives me a short list of candidate words and lengths to try against the crossings.
Next I scan the rest of the clue (if there is any) for wordplay patterns: charade pieces (like W + AN), hidden runs, reversal indicators, container indicators, or homophone hints. For example, W (west) + AN (article) is a cute charade that actually spells 'wan' and is used sometimes to misdirect. I also check for simple substitution tricks — 'wan' could be clued by 'pale' synonyms or described as 'lacking colour' in a more poetic clue. If crossings are sparse, I keep a running list of plausible synonyms and come back after filling easier slots.
Finally, I try the tone of the surface: many setters favor gentle misdirection or a bit of definition redundancy. Keep a shortlist, test with crossings, and don't be afraid to step away for five minutes — I often return and see the right fit instantly. It still feels satisfying every time.