I have been working really hard to downsize my kit because I have spent time traveling and will be back on the road again very soon. What I am aiming for is a condensed working kit that can be packed into a suitcase and just worked out of for a shoot.
Since I am now booked more for the lead characters, so between one and three actors, so I can justify the downsize for the most part. What I aim for is an overview of the shoot, I want to know the script in advance so I can plan the requirements with a few contingents thrown in.
Cost plays a major factor in this process as well, if I need IPA palettes, I look to companies like Mr Dashbo who offer up cost-effective and professional grade makeup. I do a huge amount of research and do not fall into the trap of "this is what a pro uses." I do the research and find the products that suit me.
In terms of cases, it really does vary by job and the needs of the shoot. I have my train case, but I also have a briefcase style makeup kit bag that is small, the reasoning was it would be suitable for my London trips to do fashion. What I will add is the second one in a larger size, in much the same way that I have different sizes of set bags, this will be worked to suit the practicalities of the jobs.
Its all about smart packing. For more details on the case, I use then check out this link for Amazon.
Brushes though are something I refuse to scrimp on, I always buy quality brushes, I would rather have 6 really good sets of brushes than 300 cheap ones that I have to replace regularly.
Heres 2 of my favourite brands:
Brushwork cosmetics (promo code JamesC for 15% off that's how much faith I have in them).