Any 6 digit Ceramic Sport Model
1. Recolor Insert Engraving. From molotow pens to platinum plating, there are tons of possibilities. There are SVs that will do it for you, or you can DIY, but this is a must.
2. Black hole xtal - Prof, Sonil, Crystal Clear. All are upgrades.
3. Fix DW. For sa3135/sh3135 watches, just go gen. you can find great condition gen DWs for 100-150 all day long and its a significant improvement. For 2824/2836 based watches, find yourself a TC overlay, or at the very least, shift the dial as much as possible to get the date close to center, and recenter the DW Overlay.
BONUS - Get it rebrushed/polished by one of the SVs and service the movement
5 Digit Sub LN - Specifically the new JF 16610
1. New DW. Might as well go gen since aftermarket are ~ half the cost, but some arent even close to good while others are passable. Its hit and miss which you get.
2. Brush/Polish/Reshape. Case and bracelet can use some work to get it as close to gen as possible.
3. Service the SH3135. A properly serviced SH3135 is a great movement. The latest ones are much better than the original versions, but sometimes arent properly lubricated or cleaned from the factory.
On the newest JF LN, the insert is scary good, as is the dial and hands, so no need to replace or mod those.
ARF Daytona
1. Shave Pushers. Chrono Pushers are a tad long. can shave them down to make them appear more gen like
2. Silence the rotor. A drop of D5 goes a long way on the rotor and makes it go from a jet engine everytime you move, to a quiet prius.
3. Or just go with a noob caseback, remove deco plate and swap the rotor for a gen 7750, or even a rep 7750 standard rotor. This brings the overall height of the watch to gen spec. Dont forget to get a new screw for the new rotor as well.
BONUS - I like putting a double AR xtal on it. Not gen spec, but makes the dial pop.