The trick is to first figure out if you can combine 5 6 or 8 together, then use the negative numbers to subtract as needed to reach you number. If you add 5 and 6, that is 11, but -1 can make 10. When you add 8 and 6, that is 14. But good thing you have the -4 to make 10. You start with the smallest number found from adding together two numbers from the positive pile like 5 and 6.
You can make other combinations as well. 11 could work too.
