@Kelly I have been the same way. I have read so much about how to actually tuck and it was only this morning I figured out how to do it. Now what I need is a method to keep everything "in" when tucked. I wear the tight panties and control top pantyhose but I do not think that will be sufficient to remain tucked inside. I also agree on the unfemaleness of gaffes so I will experiment with tape and see how that goes.
Now, Kelly, I will tell you how I did it. My things are not very big and from time to time (often when in an intimate setting with a woman) my right testicle would sort of pop under and not be visible. This used to worry me somewhat until I put 2 and 2 together and figured out this was tucking! So this morning in bed that right one just sorta did it and I left it there and fiddled with the other other one until it popped inside too. I felt great and have been on sort of high all day because this was something I have wanted to achieve. I think any real movement, even getting out of the bed causes everything to go back to its normal position and thats why I will need something really tight there to hold them in place.