Besides the basics of not typing your code all over the place, most of the time I personally just find using the stuff you mentioned like \\\\\Note\\\\\, \\\\\Voice\\\\\ to be enough to keep myself organized. .hps files can get quite large, but very rarely do I ever run into a situation where such a way of organizing is unfeasible.
If your .hps does get ridiculous for whatever reason though, I guess you could add a table of contents at the start, and ctrl+f to where you want easier. Like this:
/////////////////
1a Hit
2a Scary
3a OogyBoogy
////////////////////////
//////////////1a Hit
void blahblah
{
}
//////////////2a Scary
void blahblah2
{
}
///////////////////3a OogyBoogy
void blahblah3
{
}