Well, I try and give some input. You can take it for what it's worth. Admittedly, I haven't had the experiences as some around here in sheer length of trips, but I've spent enough miles and nights in vehicles to have formed my own opinion of things I guess you could say.
For me, once you get into the proper mindset, the outfitting will do itself (along with some money). Though some people around here view this hobby as just another vehicle obsession, it's much more than that. People have been overlanding for a long time. Many of our parents and grandparents did it with bone stock vehicles and camping gear. But without the means of transportation it is literally just camping.
So with that being said I try to focus on sheer reliability first. If you haven't already, go through all the vehicle systems and make sure they are tip top. Along the way gain a working knowledge of the systems. A little knowledge can be the difference between a fun trip, even if limping home, versus a rescue mission. Bring spares for the essentials. Obviously fluids are a good start, drive belts, etc. No one expects you to carry a spare driveshaft or something, just use your judgement.
From there my mind goes to protection. You've got the vehicle reliable, now protect it. Skids, diff guards, things of that nature are all good. Some are more necessary than others. Once again use judgement.
The next logical step is capability. If you can add clearance, strength, flex, etc. in a reasonable way that doesn't sacrifice the reliability or safety of the rig, go for it.
Other aspects to start looking at next would be self-recovery capabilities and range. Winch, shovels, extra fuel cans, etc. can all help out here. From there comforts might be next such as a fridge, better sleeping arrangements, etc.
Sorry, I know this is all a bit theoretical. It's just the way I approach things. Some of the things I listed may be higher on other people's priority lists. I ask if I could do a one day trip...then a weekend trip....then a week long trip...then a month long trip. If you go after it like that, you will likely mod things in the correct order.