The #1 thing is shoot at the same frame rate from all cameras on all events for a given project. You don't want to mix 24 and 30 fps material unless it's unavoidable. This is because conforming 24 to 30 requires 3:2 pulldown:
https://en.wikipedia.org/wiki/Three-two_pull_down. It's OK for an entire program -- in fact we watch movies on TV like this. But when rapidly switching scenes on serious material that was shot with intermixed 24 and 30 fps cameras, it doesn't always look right.
Conforming 30 fps to 24 fps is even harder, but with modern digital processing such as optical flow and motion estimation it can be done. However it's ideally best avoided.
The #2 thing is consider the playback mechanism. Traditionally you want your shooting frame rate to match this. Thus 24 fps for cinema and 30 (29.97) fps for TV. However with increasing use of streaming video and computer playback, it's more complicated.
E.g, some streaming video players (inc'l Youtube, I think) formerly played 24 fps material at 30 fps, so they were internally doing 3:2 pulldown. More recently I think Youtube can play 24 fps material at 24 fps, so this is less a factor.
But if your distribution will include Youtube, Vimeo, Blu-Ray, etc, you have to investigate and consider all these.
In general a common practice for mixed (but predominately web) distribution is shoot at 30 fps for shorter form material and 24 fps for longer form subjects.
None of this will make much difference when shooting DSLR video if the camera is set to aperture priority or fully programmed. In that case the shutter speed will be constantly varying, and even though the frame rate may be fixed at 24 or 30 fps, the resultant material often looks poor. IOW if you get so fixated on frame rate and forget about shutter speed, this can negate any artistic or technical goals.
Shutter speed should generally be locked at about 2x the frame rate (e.g, 1/60th sec for 30 fps). This is called the 180 degree shutter rule.
https://luispower2013.wordpress.com/2013/03/12/the-180-degree-rule/
This requires shooting DSLR video in full manual or shutter priority.