paint mixing question

I'd like to use my airbrush to paint all the parts in a kit, but I usually only use it for the bigger pieces such as chasis, body, and interior tub. I just cant stand the time it takes to get the paint thinned correctly, and get all set up to paint. So my question is, can I thin my paint in advance? I saw some little squeeze bottles at a craft store that looked like they would be perfect to store the paint, but they were plastic. Im not sure if the paint would dry inside these or not. I use Tamiya acrylics most of the time. Does anyone else do this? Any feedback would be appreciated.

I thin paints I use a lot in advance, for example, I always have a bottle of pre-thinned X-18 on hand as I use it so often.
Thinned paint will store for a short period of time provided the container it is in seals very well as in airtight.
I don't recommend thinning paint and expecting it to last for more than a month though, for some reason, I've noticed they tend to degrade over time.