I don't do anything differently solo than tandem, except maybe pick more adventurous harder/longer routes solo, since it's only me I have to convince I want to do that, and its easier to arrange.  I don't cary a spot or PLB or anything else, either solo or tandem - I guess I'm likely to fish more on a tandem trip though.  Typically, I plan on 15 to 20 mile travel days depending on the number of portages involved

in either case, I'm packing as light as I can, and travel most days - maybe one or two layover days out of 10 or 12

there have been many many threads on the topic - instead of doing a "search", just scroll backwards thru the thread index/list