What you may want to consider in your quest for FS/MSH modifications is your desire for increased grip (traction) vs. aesthetics. If it were me, I'd first consider which of these two aspects is most important, and let that weight heavily in my decision making. Further, is the gun primarily for carry, competition, range use, or is it a safe queen (let's be honest, it happens...)?
You may determine that aesthetics are #1, as you feel the need to jazz-up the gun a bit. Let's face it, looks are important. Sorry, but I can't help you much here, as looks are subjective. I would venture to say that most folks find both checkering and snakeskin patterns to be quite attractive, and find serrations, matting, and stippling to be nice, but somewhat less visually appealing. Note that I said most folks (certainly not all). Personally, I find any well-executed treatment to be visually appealing, other than coarse checkering, tiger-tooth stippling, or uniform (read: factory) serrations. Patterned serrations, on the other hand, can be very appealing, but do not necessarily come cheap.
You may determine that traction is most important, and this again, is shooter-specific. Some individuals want or need maximum grip, while others feel that their hands offer adequate grip strength, or choose to get their traction from the grips, as SXT indicates. Again, I can't offer you much assistance, except to say that some folks find coarse checkering to be so overly aggressive as to cause bleeding and tenderness with extended shooting sessions. Conversely, while some may find a gun that is smooth fore- and aft to be too 'slippery', others, especially CCW types and even some competition folks, actually desire smooth, for it's relative inability to snag and abrade, and for it's ability to offer a consistant grip purchase when time (draw speed) is a factor. Here, think sliding your hand into a proper position, quickly and with high repeatability. Again, some folks find a good compromise between speed and traction coming via the combination of smooth FS and MSH, combined with non-smooth grips. Personally, having come full-circle, I would probably fall into this category. Serrations, being aligned with the longitudinal axis of the frame, also allow a fast grip, plus additional traction.
Hopefully you can determine that there is no one "best" treatment. Personally, I wouldn't give a lot of credence to what anyone here offers; myself certainly included. It's much better to take the time to find out for yourself what works best for you, provided you have the ability to do so. Searching through the various forums here, you will certainly find something that trips your trigger, so to speak.
There has beeen a lot of commentary here about checkering and serrations, but I also wouldn't forget about stippling (also offered in many grades of coarseness) and matting. Before his accident, Terry Tussey used to offer a treatment that was kind of a combination between very fine stippling and matting, which I thought was about the most functional and attractive treatment for me, personally. He used to use an expensive maching, I believe called a 'Gravermeister' to execute this treatment, and he executed this treatment flawlessly. Need to see if I can pick up one of these. :rock: Anyhow, HTH, and good luck in your decision.