You can combine regexes with macros if you only wish to run your macro on a particular set of lines:

    :'<,'>g/foobar/norm @q

will run the macro only on the subset of selected lines that match the regex "foobar". :g/.../ will match the regex against all lines in the file.

I love the g command. Very useful to quickly cull out lines of stuff that you don't want in your file. g/foobar/d

@@ applies the previously applied macro, so after applying the macro (including the move to next line, but see below too) you can you just hold down @ and quickly go through as many lines as you need. If you overshoot, you can just press u a few times.

Another tip: when you forget to add the move to next line to your macro, you don't have to start over. You can append to a macro, just use the upper-case register name instead. So to append a down and move to beginning of line to macro 'a', you'd type qAj0

Both useful tips. I knew the macro is really just replaying whatever is in the register but it's good to connect the append dots to the equation.