You seem to misuse vim, but that's likely that you're not very familiar with it.
The right way is to press Esc, go where you want to do a small correction, fix it, go back and keep editing. It is effective because Vim has much more movements than usual character forward/backward/up/down. After you learn more of them, this will happen to be more productive.
Here's a couple of use-cases:
- you accidentally typed "accifentally". No problem, the sequence EscFfrdA will correct the mistake and bring you back where you've been editing it. Ff movement will bring you back to the first encountered "f" character. Compare with Ctrl+<-->->->->deldEnd, that does virtually the same in a casual editor, but takes more keystrokes, makes you move your hand out of alphanumeric space of the keyboard.
- you accidentally typed "you accidentally typed", but want to correct it to "you intentionally typed". Then Esc2bciw will erase the word you want to fix and bring you to insert mode, so you can immediately retype it. To get back to editing, just press A instead of End, to reach which you should move your hand
- you accidentally typed "mouse" instead of "mice". No problem - the good old Ctrl+W will delete the previous word without going out from insert mode. And it happens to be much faster to erase small word than to fix errors in it. I'm so used to it that I had closed the browser page when I was typing this message...
- repetition count is largely underused. Before making a movement, you can type a number; and the movement will be repeated this number of times. For example, 15h will bring you 15 characters back and 4j will scroll you 4 lines down. Start using them and you'll get used soon and find out that pressing 10 times <- key is less fast than iterative approach to moving cursor, when you type 12h, notice that you made a mistake and immediately correct yourself with ll.
But, if you still want to do small text traversals without leaving insert mode, follow rson's advice and use Ctrl+O. As an example, Ctrl+OF+f will move you to previous f
character and leave you in insert mode.