What You Need:
Two padded envelopes - two sizes, one of each 6"x9" and 8.5"x11" (avoid using the "plastic" coated envelopes, in rain or snow, the ink on the address can smear)
One plastic ziplock bag (sandwich sized)
Small piece of tissue paper
11 Forever stamps
And, as with any average TTM request, a short (2-paragraphs/half-page), hand-written request letter to the player.
How to put it together:
Step 1: Wrap the baseball in a small piece of tissue paper. Place the wrapped ball into the ziplock bag and close the bag. Make sure all air is out of the bag.
This was one of the things that I started doing as a result of early experiences. Originally, I used to just put the ball into the envelope without cover. This resulted in both a smearing of the signature and, once some damage from the pen. These materials can be reused - often.
Step 2: Address both envelopes - don't forget the return addresses.
The large envelope should be addressed to the player, and the small one will act as your return envelope and should have your address.
Step 3: Put five Forever stamps on the small (6"x9") envelope, and six stamps on the larger (8.5"x11") envelope.
Honestly, I don't know the exact required postage - but, I have used these amounts for years, and have never had any problems. You can take the envelopes to be metered if you are nervous.
Step 4: Put the small, return envelope into the larger envelope.
Step 5: Put your request letter in the larger envelope.
Step 6: Put the ball in the big envelope.
At this point, it is a fairly tight fit. Don't be scared to stuff it in there.
Step 7: Seal the large envelope.
I usually just use the adhesive provided on the envelope (i.e. - no additional tape, etc should be necessary).
Step 8: Mail and wait.
Hope these tips help you expand your collection of autographed baseballs...