It does depend on how much you think you might add later.
For my uses (heated grips, GPS and phone) I just used the supplied accessory connection under the left fairing. I got the Honda harness as well. Not really needed, but, it was only $15 and it meant I didn't have to hack into the bike's wiring harness. It is fused for 10A and is switched.
I installed a powerlet and cig lighter socket in the right fairing pocket. The powerlet was used for the heated grips. Cig lighter for phone. I made up a 5V inline converter and wired the GPS direct. If I had it to do over I'd skip the powerlet and just install the cig lighter. Wire heated grips direct to the accy harness.
When I had some LED front marker lights I also wired them into that harness.
If you are going to add some higher power stuff, like driving lights and heated jackets and such, then an additional fuze block would be in order. It is easy to add later.
Last, cig lighter socket location. I would not put it in the fairing pocket again. I'd find a spot on the dash to install it. The 'grills' would be a good spot. I just found that the pocket is such a handy thing to have it is a shame to have to work around wires in there. On most trips I even removed the lid so I could get to stuff in there while riding (at least when not raining
).