I have one preset for each song I am playing. Bank size on the MFC-101 is zero, so I use the MFC in song mode (thanks, MFC-edit) with a reverse setlist and switch to the next preset/song using bank down switch (easier than bank up, since it is at the bottom of the MFC). Or I just use my iPad with Setlist Maker.
I have my scenes arranged in the order I play them for each song, so I just switch SCENE UP (which is programmed to the bottom switch on my MFC EXT module) for every scene change. Thus, scene 1 may be intro, scene 2 may be first verse, scene 3 may be first chorus, scene 4 may be second verse, etc. In other words, scene 2 may be the same as scene 4 for example. But that means that all I have to think about while playing through the song is hitting "SCENE UP" at each scene change. And I rarely need more than 8 scenes for a song.
IA1-8 on my MFC are configures as SCENE 1-8, mostly to display what scene I am on. And - for the rare preset which requires more than 8 scene changes, it allows me to jump between the different scenes as required.
I also have a springloaded Mission SP-1 (with toe-switch), and I have configured the toe switch to SCENE UP as well. This allows me to change scene while riding the pedal for any effect I might be using.
The remaining IAs on my MFC are configured to my most used effects (drive, delay, reverb, etc) - and are there mostly as on/off-indicators. I almost never use them, as all my songs are organised in the way I have described. They come in handy when rehearsing though, when I might want to switch off drive and/or delay when practising a part.
This setup means I will only use two switches playing through a set; BANK DOWN for the next song - and SCENE UP when required during the song. Great stuff, and it allows me to concentrate more on my playing - which I REALLY need to
(A couple of songs need two presets, but then they are arranged in reverse order so I just hit BANK DOWN iso SCENE UP when required)