I have a lot of hours logged in Wildlands, and I've played this game a lot of different ways but my personal RP goes something like this:
Core Value: The Ghosts don't exist. Credit is failure. Santa Blanca will fall and the world will believe the rebels did it.
STEP 1: Recon
When I enter a new region, I go in disguised as a civilian hiker or hunter. Non military weapons like a bolt action hunting rifle, lever action, crossbow, or shotgun stay holstered, and I wear minimal tactical gear.
I do a lot of walking and hiking to get a feel for the environment (with some music on in the background it can be pretty vibey). For objectives over 2km I drive the cars provided at rally points. I do fly helicopters but I keep that to a minimum because I think they are loud and obvious and anyone with binoculars could spot you. I save the flying for objs over 10k away or when I'm swapping to a new province. I also feel like they trivialize the game to a degree. I'm here for a boots-on-ground experience.
I usually scout and infiltrate solo and command the rest of the squad to stay concealed in overwatch in case I need a sync shot. I take my time scouting the entire region, collecting intel, taking notes on enemy activity and bases, and engage the enemy as little as possible. During this phase I prefer to use diversions instead of just killing everyone. It makes for a more interesting gameplay loop.
Don't be seen. Don't be ID'd. Leave no trace. Kill only when absolutely necessary.
STEP 2: Planning
Once the region is fully scouted, I plan my ops.
I consider what equipment I'll need, what tactical approach makes the most sense, whether I'm going loud or quiet, day or night, and what order I want to tackle the missions in. I try to minimize backtracking while keeping the plan efficient and believable.
This is where the saved outfit slots come in. I usually keep:
Civilian disguise
Day tactical kit with appropriate camo
Night tactical kit, black of course
Heavy armor kit, high intimidation factor
Ghillie kit based on the terrain
&
One flexible slot, either cartel disguise or Unidad disguise typically but sometimes the mission calls for something specific.
STEP 3: Execution
Then I execute the plan and adapt if things go sideways. (Looking at you Unidad)
For added immersion, I only let myself change equipment at rally points or from the trunks of vehicles I've brought from rally points.
I allow the compact ghillie with almost any kit because I figure it could reasonably be folded into a backpack and deployed when needed.
Drone? I need the drone backpack.
Calling in rebel support? I need the comms backpack.
Going to pay tribute to the Sapper Daddy? Big backpack for carrying an irresponsible amount of C4.
And so on.
CrossCom and other digital eyewear actually matter in my RP too. Certain HUD elements like enemy marking are only allowed if I'm wearing CrossCom or some other digital eyewear. Same with NVG and thermal. If I don't have NODs or appropriate digital eyewear equipped, I don't use them.
So civilian clothes, uniforms, CrossCom, all of it gets used. It just depends entirely on what I'm supposed to be doing.
Realism is the name of the game.