For the real thing;
If you use the staff, write the rhythm over the staff for the first one to three hearings.
try to also work backward for the last note, like, does it come from above or below? Does it go up after the first bar? Also, always make sure all of the first notes are in for the time signature before drawing the barlines.
accept that the 3rd bar will always be hazy and focus in the 2nd and last bar the first 2 hearings. As soon as you hear that second bar sing it back in your head (don't wait for the 3rd bar to confuse you). Then see if the last bar is a high or low do and get the last few notes they usually move in step to the do or move by the do/mi/so/do/so/mi/do triad. If you are stuck with ryhthm just say "slow" for crotchets and "quick quick" for quavers. Slow Slow Quick-quick Slow