There are certain products that are great to have around to 'finish' your look. It's always a good idea to have a razor comb on hand for doing those subtle trims so that your own hair gradually blends in with the hair system. Debbie sells a Professional Razor Comb on her site for only $10.99 plus S&H. Check it out.
Regards,
John

sorry for this dumb question, but how does it work?
Does it cut your hair on the sides as you comb?

Yes, it's a comb with a razor in it. As you comb your hair the razor cuts off a small amount of hair. It makes a smooth and even cut. If you want to keep on cutting more hair off you just keep on combing till you get the desired result.

I will caution new users that to be very careful with this device, it is great but you can butcher a piece with one swipe.

Practice with an old piece or when your new piece is longer.

Gel is a master with this and don't be afraid to offer up a post requesting his techniques and advice.

I've got one of those and use it sometimes, though I prefer to use simple Bic disposable shaving razors. Cheap and readily available there's less risk of cutting off too much at once. You may go through a few of them to cut in and blend one unit as the hair tends to clog the razor, but they work a treat and are easy to use.

I have something similar in my box of goodies. It was even handier when I wore a smaller unit, but even with the full cap I have used it to knock down "high points" whenever necessary. Just make sure you only take a little off at a time and you'll be ok.