Root question about changing themes...

[Raekwon]

When changing a theme is there anything I need to do about the old theme first or just wipe cache, dalvik cache and flash the new theme?

 

[Rxpert83]

You got it. Nandroid, wipe and go.

If it doesnt work. Wipe dalvik cache, Cache, flash the ROM you are using(this undoes any prior themes), then flash the theme

 

[MizzouBrent]

When changing a theme is there anything I need to do about the old theme first or just wipe cache, dalvik cache and flash the new theme?

Or if you're talking about AOSP roms, they are easily changed via the theme chooser app.