If you want to try and create a tape a simple method could be to write a set of affirmation relating to the belief you want to strenghten. Each in 3 forms for good measure (eg I am, you are and (your name) is.

Have a list and put on some ambient background music (something you find relaxing, even nature sound. You can create a nice waterfall or rain sound by putting a cardboard box in the shower turn on the water till you get the sound you like and record it.)

With that set up you can put in a relaxation bit at the beginning of the tape... telling yourself to relax. About 3 to 5 minutes and then read the affirmation with the background running. Read the affirmations so that you have about 15 to 20 minutes of affirmation. Then give yourself a count up to feeling alert

If you want to make it semi subliminal... skip the relax and just record the affirmation in a soft voice allowing the background music to be stronger. You could experiment by walking to different parts of the room while saying the affirmations. That way you have a tape you can play in the background. Its probably also easier since you only need to record the affirmations once (if you have a second tape player it) If you're looking for something to play music and only have one tape recorder remember you're computer to play the music. No doubt many are able to use the computer for the whole deal. Just the manual way of doing it will give you a very solid foundation of acquiring the beliefs you desire.

Alex