Jump to placeholders with <c-j> and <c-k>

placeholder_jump.vim

" Install by saving as plugin/placeholder_jump.vim in your config files.
"
" Search for <+text+>, <+other text+>, <++> etc, and enter select mode on top
" of the placeholders.

let s:placeholder_pattern = '<+.\{-}+>'

function! s:Next() abort
  if search(s:placeholder_pattern)
    exe "normal! va<o\<c-g>"
  endif
endfunction

function! s:Prev() abort
  if search(s:placeholder_pattern, 'b')
    exe "normal! va<o\<c-g>"
  endif
endfunction

nnoremap <c-j>      :call <SID>Next()<cr>
snoremap <c-j> <esc>:call <SID>Next()<cr>

nnoremap <c-k>      :call <SID>Prev()<cr>
snoremap <c-k> <esc>:call <SID>Prev()<cr>

Many thanks, this helped me achieve my goal (I know nothing about plugins and vimscript so far). To work exactly like in vim-latex (where you can trigger these while in insert mode), I had to add two lines that look like the snoremap ones but start with noremap! instead. Hope I did that right

Or do I want inoremap? I guess, yeah.

For insert-mode, inoremap is the one you want, yeah 👍. I haven't used noremap! myself, but it's apparently for both insert and command-line, and in your case, command-line doesn't matter.