некоторые is more of a defining word
какие-то is more of a wide variety word

So it depends on what you want to say:

некоторые дома would sound like you know which houses you're talking about, just don't want to name them
какие-то дома would sould like you only have a vague idea of which houses you're talking about.

So saying:

Я пообещал послать вам фотографии каких-то домов would mean - um, I know I promised to send you some pictures of certain houses, I've just forgetten which ones, care to remind me, please?

Я пообещал отправить вам фото некоторых домов - would mean that you promised to send some photos and you're going to deliver

P.S. Saying кое-какие will also work in place of некоторые

Я пообещал отправить вам фотографии кое-каких домов.

In fact I would personally have used кое-какие, but that's just me.

One last thing, некоторые in that sense is very close to the English word "certain"

Cheers