There are a few methods to make things easier. If you are intending to enter cards for trade, enter those first in the set simply by checking the individual boxes. When done, use the drop down menu to transfer everything to For Sale / Trade. Then enter your set keepers.
A better method is to create multiple collections. If you look at my collection(s), I have my PC, a collection for every card company, minors, and miscellaneous sets. I also have a Traders collection. By entering them in multiple collections, the check boxes are available all the time to check what you have.
If you desire to enter multiples of any cards in a particular set, use the "Add Multiples" feature on your collection summary page for that set. These can be for Keepers or Traders.
Plenty other suggestions out there; if you can't figure something out, just ask. Plenty of helpful members here. And don't look at it as a chore; enjoy going through your collection as you enter it. One set at a time, it will all get done.
Bruno
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Check my Profile page to see my 2023 Goals and my Lists of sets near completion (5 cards or less) or sets getting close (less than 100 cards missing and 75% complete).
https://www.tcdb.com/Forum.cfm/Page/B/ID/0/?MODE=VIEW&ThreadID=25745&C=0