I'm a special ed. aide that works 3+ days a week in K.
This is more about when your kids go to K, rather than the screening.
I would focus on self-help skills, making them independant (for their age).
Practice tying shoes.
Zippering coats.
Unbuttoning pants for potty.
Using a kleenex.
Putting on winter gear-- if you live in that type of climate.
"Body basics"..... sitting criss-cross, walking in a line, keeping hands to oneself, etc.
In the beginning of the year, we spend tons of time working on these skills!
Kids who already have these mastered display much more self-assurance. Plus, the more kids that know these skills, the more we can focus on actual academic learning!