Hi, everyone! I spent the last few days searching for something similar to this, but since I couldn't find it, I decided to post this. =D
I know that many bloggers have problems with HTML and everything (too difficult to pick up, etc), and yet still want to use widgets (if the theme allows). I've been using this method to help generate the HTML codes for text widgets, and it saves time and trouble!
Use your "Write Post" feature to help generate the HTML codes you need for your text widget!
A step-by-step guide to do it:
1. First, go to "Write Post" or "Write Page", whichever you prefer.
2. Click the "Visual" tag, if it isn't already in that mode.
3. Use it to type anything that you want in your text widget (links, pictures, etc), as you would with your posts/pages.
4. Click the "HTML" tag, so that you can see the HTML coding of what you've written.
5. Copy the whole HTML coding and paste it into your text widget.
6. Don't forget to click "Change" and "Save" to save your changes!
7. Voila! Your very own custom-edited text widget!
It may be easier to read here (screenshots included):
The only disadvantage with this method (that I can find) is that you'd have a draft post/page in your list, due to autosave. O_o
It may be a simple trick, but hopefully this helps! =D