I use the core set 1s and 5s. I have them laid out in a column of 5s, and a column of 1s in stacks of one or five, with stacks of five 1s behind individual 1s, to make it easy for my opponent to see. It looks something like this, but organised vertically instead of horizontally:
[5] [5]
[1] x5 [1] [1] [1]
Alternatively i put the 5s and stacks of five 1s in the same column, like this:
[1] x5 [5] [5]
[1] [1] [1]
I’ve found the latter method clearer and it’s what i do if i don’t have the space. If i do have the space i might do this:
[5] [5]
[1] x5
[1] [1] [1]
Also, at the end of my turn i tell my opponent how many credits i have and how many cards i have in my hand ( HQ or Grip ).