tongue and groove ceiling
" leave any splice on a rafter" or joist. Good advice, but nail thru tongues, avoid face nailing as much as you can. Can also lead to a joint pattern repeat so pay attention. You may wind up going upstairs and adding some bridging as nailers break joint patterns. If flooling (just invented the word) runs parallel to joists you'll need furring strips, but you knew that. Install wall to wall on proper centers for your planks and some shorter ones spanning at least 3 joists half way between longer ones. While installing planks be aware of where joints are going to be several rows over. Adjust lengths or add nailers to keep butt joints as random as possible.
Seems like I'm overly concerned about joint pattern, but I've seen some jobs where they were glaringly obvious, ruining other wise great job. Picture wallpaper, gift wrap, sheet flooring where repeat is too close, tiles or pavers that imitate stone or wood but not enough wariation in patterns. Lighting on ceiling may make joints show more.
Measure twice, cut once.
Look at the nail, not the hammer. Watch the fence, not the blade.
If you hook your thumb over your belt you won't hit it with the hammer or leave it layin on the saw table.