This is where flexi-syns comes in to play. You make a conscious decision on how many syns you will use for that event and stick to that. So, have your syns as normal every other day and then, for arguements sake, you have decided to have up to 50 syns for that event so you stay under 50 syns at that do.
That way you are not depriving yourself at all, enjoying your event and staying on plan.
This is a once in a while thing but you don't have that feeling of being a failure for going off plan.