Boy, that blazonry thing has so many words! How are you supposed to remember them all, let alone type them when they have all those weird spellings..? You've tried that "Build a shield from parts" thing but its waaay too limited, like there's only about 10 charges! Pah.
Fret no more mouse-warriors - the "Build from Parts" page has had a major update!
When you load it up, you are first asked if you want to create a simple shield or a complex one. The "simple" route is identical to the previous version - there aren't many choices, but everything is explained quite clearly.
On the "complex" route you'll have access to much, much more. Instead of a handful of colours, divisions, ordinaries and charges you have the choice of almost all of them! And you can add modifiers, place charges and so on.
The downside of course is that there are lots and lots more images to look at and many more clicks to work through - be prepared for click fatigue!
Even so, you may find it useful as a way of prototyping shields without doing a lot of typing. You can undo your most recent actions, see how the blazon is built up as you click on things, download the finished product as an image or copy it over to the create page for further work.
Obviously there are still many, many things that you can't do - quartering and marshalling in general is the largest area, but you can't chose different shield shapes or colour charge features with a different tincture. For maximum power and flexibility the "Create Page" is the place to be, but for a quick fix, give the "Build from Parts" page a try!