Any move where you have space ad can, move your own valuables and financial documents. For example, we have always moved CONUS (in the states) and driven so we we have moved photographs, documents, family heirlooms, etc.
As far as the movers...seriously, it is hard to relax about it the first time. Make sure you just keep moving about the house so they know you are there....have extra hands on that day too. Most are reputable and honest, but a few spoil it for everyone.
We have always provided lunch (pizza or subs) and lots of beverages (soda, water, gatorade)...but have never tipped the movers.
Remember that anything you pack that they move, you are liable for, not them - so let them pack it! After they leave and all the boxes are just there, we sometimes make sure that all the boxes are properly labelled and sometimes write our name and job number on sides of the boxes they havent. Also, the little move stickers they put on things either stick forever or fall off...so sometimes we will tape over them once the movers leave, if it is something that the tape wont ruin.
Empty your trashcans, cause they will move trash!!! And, set aside or lock up in one room all the items that you are moving yourself so it doesnt get mixed up in the packing of the day.
Finally...I havent always done this, but glass packs better with glass....so if you have glassware in several rooms and consolidate it to one, it should all get packed together.
DO NOT polish your furniture the week they come to pack you up....the polish can soften the finish and then the moving blankets can leave imprints. Dont go nuts washing everything either....ie, drapes, blankets etc....wash when you get there as it will need to be freshened up anyway.