This isn't about one-handed control, but still related to layouts. Specifically about icons. It can really get confusing, especially if you don't use something regularly and want to put it on a chart like I have installed within my lap desk. Part of the problem is that I want to pretty much have everything listed on that chart, but that's a LOT of layouts, such as:
Alpha, Alpha shift, Green, Green shift, Numbers, Numbers Green, Edit, Edit Green, Functions 1, Functions 2, Media, Apps, Emoji. Try to fit all that, plus other notes, on one 8.5x11 inch piece of paper! I can combines some, like Alpha and Alpha shift since most changes are just upper and lower case so I only put one in the chart. The things that change to an entirely different character aren't an issue either since, for example, it is easy to fit "; :" into one cell. But with many of these things, you can't do it with individual characters. You need a description (for example, "cpy" for "copy" (so I can make the characters a bit bigger in the cell. Or an icon which, of course, takes up more space than a character.
I figure some of this is going to be unavoidable, but I want to avoid as much as I can. So....
Consider anything involving a right arrow of some sort. In the TB app, there are 14 symbols involving that concept. Sometimes a ">" type symbol, other times a solid triangle shape pointing right. Might have a double symbol. Or might be combined with something else, something like ">||". Some are pretty ingrained. Like my example which would be "play/pause". That goes back decades on tape recorders. But other things are less clear. WT does have some with enough other info to make it clear. Like an arrow with "app" written above it for next app. But not all.
So, in my search for other ideas, I considered "Find" combined with "Find next" and "Find previous". As expected, WT has the standard magnifying glass for "Find", but the other two just use ">" and "<".
So my idea was to use the same basic symbol for all three, but with an adjustment as below:
The vertical one is "Find". The one tilted to the left is for "previous" and the one tilted right is for "next". Another option would be to use one icon for all 3, but under the previous and next ones, include an arrow pointing the appropriate direction. The thing is, you could tell at a glance that all three are about searching.
Still working on other options, but I'm no artist so even when I have an idea, I'm not one to created it.
For example, consider Page Up and Page Down. I could see having a page icon, but with an arrow in each, stretching from near the bottom to the top (or vice-versa) to show page up or down.
Maybe a "document beginning" and "document end" could do the same, but instead of having a one page icon, show two vertical pages with the arrow passing through both to symbol you'll be going beyond a single page jump.
Paragraphs are still a mystery to me as to how to make a clear icon without getting crowded. Same applies to a number of others.