I am a bit of a stickler for geography in my own campaign. I constantly consult several maps and maintain a few for me to keep track of landholdings and points of interest. For the most part this is just to keep things straight within my own head as I plan into the future and try to connect things - abstracted locations don't work for my brain unfortunately. For weird places, I am fine with just saying "in the woods/fae", but for most places I try to maintain a static location. Basically I try to do a few things:
I try to adhere to travel restrictions if its appropriate.
If the adventure or task at hand is time sensitive, I try to account for travel times and distances between locations. For example, getting word that Salisbury is under attack while you are off around London means that whoever is attacking Salisbury has had a good deal of time to ransack the county before you can ride there. It takes time to react to these events, and rewards planning in advance. In the same vein, mustering an army to fight someone who's arrived on your doorstep also takes time.
If the time doesn't matter though, I ignore it. Oh you travel to Levcomagus? Yeah some time goes by and your there. You send messages to contacts to round up a few extra knights for an adventure? Sure, soon enough they arrive at your doorstep ready to fight. Unless there is a reason to bring attention to the travel times, I ignore it.
I try to make armies react to the existing geography and fortifications in their campaign.
This I haven't has as much opportunity to really play with in my campaign, but for the most part I try to have armies make decisions that account for local terrain and settlements. Specific areas of Logres boast much better forts than other areas, and for future army campaigns, I plan to incorporate them into the adventure rather than have them be ignored. Going around a fort is always viable (good thing forts dont move!), but you risk their garrison harassing you. Assaulting them is also very costly of course. I want to draw attention to specific places rather than generic areas, and forts make natural focal points for combat and such. Reading through Book of Warlord showed just how many cool and important places there are that are ignored in GPC adventures/battles as written. If there is a massive DV26 fort in the way between your army and your goal, it has got to impact your military campaign at least somewhat - maybe the battle takes place near there instead, maybe forces need to be sacrificed to maintain a siege?
I maintain my own maps that I can edit and revise as the campaign progresses.
This helps keep a handy reference for where things are and I can easily consult them to decide if the geography will matter for the adventure. If an adventure describes a new location that isn't on my map, I add it. If it doesn't say where it is in relation to other places, I usually just put it somewhere that's a bit empty on the map and try to account for the local geography in my descriptions of it. If its an explicitly fae or weird location, I'll just say its in the forest and the player's need to make a few checks to see how easily they track it down each time they try to visit. To me, the fae is in its own dimension - it doesnt follow the rules I apply for the rest of the geography, it is a realm subject to the whims of my own creativity (or laziness haha!)
This map is explicitly not an in-universe resource. Its just there for me and my PKs to reference and get a better OOC idea of the world their characters inhabit. So I can frequently adjust things without worrying about tearing the world apart and can add new locations as required by the narrative.