Just a quick tip here. You can often find these on sale at Harbor Freight for a few bucks:

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Cheap Junk Harbor Freight Wire Stripper

They are utter garbage when it actually comes to stripping wire. BUT- they are excellent for getting the last few clicks out of a zip tie!

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Excellent Zip Tie Tightener!

Just slide the tie in the side and butt the nose up on the zip head, and give it a squeeze. Works on all sizes, but is really helpful for small ones that you want to get good and tight.