Well, they are dangly bits. Dangling participles and dangling modifiers can push your readers over into a guffaw or simply ROFLTAO…ahem… At worst, not making your sentence clear can confuse the heck out of your readers.
When you’re acting as your own proofreader, it can be difficult to discover these dangling confusions if only because you know in your own mind exactly what you mean to say.
C.S. Lakin has done a couple of cute, short posts on dangling participles and dangling modifiers at which you should have a peek.
Consider creating a checklist for yourself of difficult to remember confusions!