I have done my fair sharing of playing themer :P so I thought I would pass on some basic knowledge I have picked up along the way. A lot of my learning was trial and error......and error......and boot loop.......and random success......followed by epic fail......which usually ends with a Win and a new theme.
Anyways I thought I would share some tools I have picked up along the way. Both for computer and phone. I am by no means a expert in any of this, I just dabble in it for fun.Hopefully this Inspires you to get your feet wet and try some themeing your self.
Some tools I just started using recently so I'm not completely fluent in them yet. So if you don't see a guide for it or tips its probably because I'm still learning it.
If you have any info/tools/guides to contribute throw them in the thread and I will add them to the OP. If you have any questions, throw those in the thread also maybe I can answer them. Maybe another member knows the answer or Maybe as a group we hit Google and combine all our research to formulate a answer.
Name of tool is also the download link.
Computer related tools.
ApkTool
This lets you decompile an apk for example the framework-res.apk(main component of theme) or the SystemUI.apk(status bar and drop down menu stuff). apktool will allow you to extract and modify the images, XML, and smali(better be smart to mess with this).
----also required for Apktool is a program called JRE or (Java Runtime environment.) You can grab that here
Gimp
O sweet sweet gimpThis is a awesome alternative to Photoshop. It allows you to do everything photo shop can do.....and ya, its free. So take that Photoshop.
Notepad++
This is basically notepad on steroids. Not always needed but nice to have on hand.
Android SDK
to tackle the pesky 9.PNG images your going to need SDK to use the 9 patch tool. Its located in the tools folder when you download the sdk starter kit.(you don't need eclipse if you don't plan on making your own apks.) Sdk also comes with a whole heap of other fun tools once you get started.
This next tid bit is basically if your just swapping out PNG or 9.PNG images that are already premade.
Phone tools.
Root Explorer
I have also heard people using ES File Explorer to do this. I use root explorer and it works great. Of ES file explorer didn't cut it. Then you just might have to buy root explorer.
Root explorer will let you browse your systems root directories and pull out system apks. It will also allow you to extract and zip up apks.
Zip Signer 2
Zip signer will let you sign apks and zips directly from your phone.
Useful but not necessary phone apps would be phone apps/tools would be photo editing programs like Picsay Pro