I’ve been buying bits that i have been finding i need at hand to do motions tracking. Things like tracking dots and rulers to measure the distance between tracks. So just recently i have purchased large 25mm sticky dots in white and black, I thought they would be good for tracking on green screens and large plane areas. I also got some small 5mm mixed colour dots to do some ‘whats the best colour for track points’ tests. They may not be one but wont hurt to see what shows up best on the camera. Also the 5mm would be good for performance capture i.e facial. I never seem to have a ruler to hand so I have gotten a 1 meter pocket tape measure to measure distance from tracking dots and also a surveyor 30m tape measure for projects on a larger scale. This will be good for measuring the distance from  the camera to the object.  I’m sure there will be other things that might pop up but thats all i have so far.