All those little details add up to one beautiful deck.
One trick I am trying in a few places is, since I buy my epoxy by the gallon and don't always use it as fast as it's said it should be used, I use generous amounts of it in places about the property. The deck being one.
When I pulled the old railing caps, some of the wood had taken hits. One was bad enough I had to swap it out for fresh. All the others, like nail holes they'd made putting them in from the top, sucked it up.
If I wanted more epoxy in, I drilled holes and injected it, then came back after that soaked in and added more, until the hole was full.
Before putting the new rail tops back on, all horizontal supports got a coat of caulking, just because. That and that all the rail tops are attached from the bottom, rather than the tops, water infiltration should be far less a problem.
When finished, all but the composite will get the usual oil based primer and acrylic.
I still have some steps to redo. The supports for those will get Henry's. The type you get in a gallon bucket, to hold down roof shingles, after any necessary epoxy treatments.
When I replaced the top pine pillar caps with cedar, I filled the gaps with hardened putty, glue as mentioned, nailer, caulking, finish & sealer. It’s not going anywhere!!! The composites look & feel so artificial. Plus their saw dust is like plastic shavings. Replacing deck boards every 20 years or so, much more fun!!! Especially, when I’m 80. Will take more pics next time..haha!!!