How do people best manage their re-print\enlargement requirements with their lab (for those that use a lab)?

Let me explain. Say you shoot 10 rolls of 36 exposures at a wedding. You send off the films and get your 6x4 proofs, which you show\give to the bride. She then chooses :

Frames 1, 5, 8, 15, 22 and 31 from Roll A
Frames 2, 3, 9, 22, 26 and 35 from Roll B
Frames 7, 15, 16, 25, 30 and 35 from Roll C

You've then got to go through your sets of negs, find the strips containing each frame, then bundle them all together and send them off to the lab who do the printing\enlarging in line with your requests to crop here and there too. They sned you back your enlargements and negatives, and you put them all back in their protective sleeves again.

2 weeks later, you get the relative asking for Frames 5 and 8 from Roll A, and 12 and 14 from Roll you dig them out again and repeat the process!

For small jobs I see this as no real problem but for bigger ones, and especially for those well established photographers who may be shooting one a week, this strikes me as quite a tiresome task when not done properly.

Interested to know how you guys manage this side of things?