I will amost always perform a second workout later in the day, working on specific weak points but with much lighter weights. For example, if my overall shoulder strength is not where it should be, and I wish to work on my snatch tecnique, I will bang out a quick workout in the 60-70% range, 8-10 sets of 2-3 reps with power snatches superset with snatch grip press behind the neck. On days where I am particularly in a hurry, I will sometimes alternate the repetitions, power snatching the first rep, lower into SGPBN, press, and lower to starting position, and repeat for three reps, 8 - 10 sets.