I employ both methods mentioned in the previous posts.
I have stick on labels from Porters as Dave stated. Use them with my DX reading T-4 and Muji II. {I save those canisters by loading my developing reel directly from the UNOPENED cassette}. As a side note: When I ordered via phone the kind sales lady asked me if I would like their catalog.Why not eh? Man oh man,it weighed a ton and I had to pay Canada Post $13.00.
Srs5694 spoke of the cassettes tossed by 1hr. photo labs. I get mine from the local camera shop who are used to dealing with student ie.poor analogers. Actually it was one of their tec. people who told me that she used the method when she was a student. Heres my methodology: I use good quality scotch tape and attach the bottom leader of the cassette to my bulk film. Then affix the top. Work the thumb and forefinger over the taped ares to get a good bond. Gently run the attached pieces into the cassette then load as usual.
One note of caution. On two occasions the film has become detached from the leader when the last frame was taken and the cameras motor drive pulled the pieces apart. To solve this possible dilemma I carry a small film changing bag if I plan on venturing far from my darkroom.