Why people always emphasis h/j/k/l when we already have arrow keys? Do you really waste a lot of time moving your fingers between them? Also, arrow keys work in insert mode.
Disable arrow keys.
It's extremely painful for the first 5 days but I promise that's all it takes to get use to it. And it makes huge difference in your productivity. All that time does add up.
Add the following to your .vimrc
map <up> <nop>
map <down> <nop>
map <left> <nop>
map <right> <nop>
imap <up> <nop>
imap <down> <nop>
imap <left> <nop>
imap <right> <nop>
The reason you want arrow keys disabled in insert mode is that arrow keys breaks the modal paradigm. Again, I promise that once you get comfortable, it becomes more efficient to go into editing mode and make the change rather than navigate via the arrow keys in insert mode.