For the sounds part I use "GoldWave", my TV sound is connect to the microphone input of my sound card.
I just create a "New" sound in "GoldWave" in Stereo at a sampling rate of 44100 Hz.
Record the sound I want, do some editing with "GoldWave". In fact the only part of the editing I do is "Noise Reduction".
Save the sound with the "MPEG Layer 3 128 kBits/s, 44.100Hz, Stereo".
And for making the ".theme". I use "Destop Themes". Go to the "Edit Theme" tab, make the change you want.
Then return in the "Theme" tab and save your new Theme.
If this could help you doing your own theme, then your welcome to thanks me.. :)