I find that the biggest problem, is lack of diverse encounters. Travel often takes days, if not weeks in game, and you can only fight so many level appropriate bands of gnolls or orcs before you just feel uninspired as a player or a GM. While it sounds rather obvious, the best way to immerse and world build, is by showing, or describing, the world to the players. A perfect opportunity to do this is from going from point A to point B. I want to look at a few things that should and probably are a part of your game, but are probably under utilized.
Weather. I try to roll for weather every day in game, but I usually fail doing that. Weather is an easy way to have an encounter that isn't combat, and can throw players who tend to build just for a specific purpose. It is also a great way to allow rangers to shine, because if we are being honest about 5e, they get few chances. The new Wilderness DM screen from Wizards of the Coast is perfect for this, if you don't already have it. I don't really intend to use this space to pitch products, but it is something I've already began using in my games, and it's fantastic because it puts things that can fill out your game right in front of you so you can't overlook it.
Weird locales. There are plenty of tables for this, and I would recommend taking from and using as many as you can find that make sense. Like weather, it seems fairly obvious, but again, it's something I don't see as often as I would like. One tip I also have for new game masters, is use as many of these as you can find to flesh out your world, and make a note of it on a "master" world map. I use a dry erase hex sheet now and then transfer anything I think should be noted into a notebook with a world map in it.
Dead magic zones. Dead magic zones aren't something I see often in 5e. Dead magic zones should be used not exactly to nerf the party, but force them to be resourceful and think outside of the box. RPG games in general allow for characters to be able to do pretty much whatever is allowed within the rules, but it tends to come down to combat or abilities to just go through the same sequences again and again. This will burn you out, and make your games boring. All of a sudden, there is a five mile area where magic simply doesn't work, now the characters have to rely more on diplomacy. Sometimes just getting players to talk in encounters works miracles for opening up role play.
A final thing I would like to add about travel, is it is a perfect way to show major events in the world, without having to shoehorn the party into it. I've played in plenty of games that have been ruined by DMs trying to create battles or some kind of major world events that just couldn't be pulled off. As a DM, it's also way more work to try to do this, and as a storyteller, it is just lazy. Everything should build in a game. Players should walk into the aftermath of a battle, or some kind of major event more than seeing it first hand, at least at lower levels. This is an easy way to push the story forward without having to force things, plus it is significantly easier to draw out events and prep for upcoming sessions as a DM then it is to just make something up on the fly.
I hope this is helpful to someone. After playing with many people I don't know over the past year because of Covid, I will say that travel seems to be one of the weaker parts of a lot of games. It's also something that is almost certain to happen in most games.
