First decide how gamey and mechanic you want it. A tried and tested but fairly prep intensive way is a hexcrawl. Rolling tons of random dice for every travel day can also be a neat way to fill a session! Roll for weather, environment, maybe a big list of random encounters, geographical features, local fauna etc pp. The dice will surprise even you, be ready to improv.

More free form ways would be to make the travel a skillchallenge/extended challenge, or use a montage approach as presented in fellowship or 13th age.

I like to mix and match the last 3 things I mentioned: random rolls, skill challenge and montage. Of course, this heavily depends on gam, too!