I am making a stacked gift box cake for my friend this weekend and she wants them to have lids.
Not sure of how to do them and everything I find says to buy Sharon's dvd. Unfortunately I don't have enough time for that! Can anyone give me the abridged version or your own technique for making awesome lids? I will have 2 square tiers and 1 round tier. Any advice is greatly appreciated - Thanks

I would just cut a thick piece of fondant a couple of inches larger than the diameter of the cake itself and drape it over the top. You could take the pan that you used for the cake and lay it over the fondant to use as a cutting guide before placing it on the cake.

If the lids is going to be separated from the cake or propped up (say by fondant "tissue paper" then I would suggest a piece of styrofoam covered in fondant.
It is light weight too.

I would just cut even strips and cut them the width of each side for the squares and hide the seems with rolled fondant. Of course make them kind of thick so they look like a lid. Hope that makes sense. for the round you can try doing one long even strip or two blending the seems. Look at Andrea's sweet cakes for inspiration she has great gift box cakes.