I like random encounters.
They add variety and some unexpected action to campaigns and adventures.
The more variety and the more your players will be interested.
However random encounters (at least most of them) shouldn't be senseless and useless and also shouldn't be repetitive.
Use the following rules.
Think about frequency
It's wrong to have too many random encounters.
Too many encounters break too much the pace of the game and PCs can lose what ae their real goals
On the contrary too few pochi are useless since they don't grow the level of variety and unexpected needed to be attractive.
As a rule of thumb, a just frequency is from 10% to 20% (in accordance with area dangerousness) for every day of travel or every hour of perlustration (if in a dungeon or similar).
Create different tables, not only by terrain (forest, mountain, etc..) but also by geographic area.
The forest in the North will have different encounters from that in the South, which perhaps will be known by your players as the Forest of Spiders.
This method, more than create variety, will help a lot PCs to remember about your campaign locations.
Try alternatives other than combat:
- have talks with travellers or merchants or guards
- try to solve sudden difficulties (to ford a river, a bridge near to fall, hazards...)
- strange encounters (a little wood made of talking trees, a haunted house....etc...)
If possibile, insert the encounter into the adventure (or campaign) storyline.
Give clues or indications that link it to the adventure or that can give new roads to explore.
From time to time, give also false or misleading clues, to let your players in a fog of mystery which is useful, ever.
Treasures and Magic Items
Give little treasure at the end of a random encounters, at least the party hasn't stumbled upon a monster's lair.
Don't give magic items. They're precious and it's better to let them as a reward at the end of an adventure.
It will be the subject of one of the following posts.