Help finishing latin tattoo .. :)

Go to a school where Latin is taught - a Catholic University is a good place to start.
Make sure you get at least three independent answers; people can be such chuckleheads.
Also, choose your words carefully; saying "is your" instead of 'were your' can be disastrous; the less words, the better.

Well, that was certainly helpful, wasn't it?

Bunch of assorted answers 3 years ago here which just shows even scholars can't agree which translation is the best-
http://latindiscussion.com/forum/latin/live-each-day-as-if-it-were-your-last.11819/

Going to go with :

Omnem crede diem tibi diluxisse supremum.
grata superveniet, quae non sperabitur hora.

Think to yourself that every day is your last; the hour to which you do not look forward will come as a welcome surprise.

Book I, epistle iv, line 13-14.

As I cant find a literal translation and I really like that