I have button boxes. Using Joy-to-key, I have a toggle that does pit board selection up / down and I have another toggle that does the value up / down. I also have a button mapped as "enter".
So I come into the pits. Toggle the select to fuel. Hit the second toggle up to tell it to put more fuel in. Then toggle the first one down to tires...etc.
Then I hit my "enter" button to get it done.