SRD

Behold:

On the face of it, there is nothing here. Flat, boring encounters with the basic, obvious enemies. Previously, I’ve written about adding extra dimensions to the encounter table. I don’t think I was right.

Instead use Surprise, Reaction and Distance - often overlooked, but essential to the variability and interest of encounters.

Surprise
On a roll of 5-6, a party is surprised. Roll for each party unaware of the other.

Reaction

Distance
If either party is surprised, an encounter occurs at 10-60’ - otherwise 20-120’.

Applying this procedure, a ‘flat’ encounter becomes something very different.

40 bandits, unaware of you - out at 60ft. Hide, encounter, call out? They seem jovial.
2 orcs, watching you closely without your knowledge. They’re uncertain - what does that mean?
12 ants, 120’ away and forming a phalanx.

Of course, using more ‘interesting’ monsters is no bad thing. I think the focus around it comes partially from a desire to sell products as novel, as well as to demonstrate the unique taste and talent of the GM/designer. Applying SRD to these encounters also gives great results - but demonstrates the ability to use anything as a point of interest. There’s a subtle distinction between something interesting in-itself and something interesting due to it’s position and relation.

This isn’t something I came up with, but it’s something easily neglected with an outsized impact on play.

I’ve made an automated thing to do this for you