DAPPER sounds like DATE PAR. How will you go on a DATE PAR?? Obviously by dressing well and being up-to-date. So Try to remember DAPPER as DATE PAR !!!!
dapper is very close to word DRAPER(Y).....SO drappery in your house is very neat and clean in its appearance.
For good marks you have to keep your exam paper dapper.
dapper sounds like rapper, eminem(rapper) is neat and trim
DAPPER = don + appear; don appearances is always neat & trimly.