In my current operator we just have a list of checkboxes to state the reasons for the extra fuel (destination weather, enroute weather, expected atc delays, expected lower level etc)
In my previous operator you just ordered whatever fuel you wanted, no questions asked.
Neither operator ever called to query a fuel decision. The carriers that pressure crews to take less fuel than they think is wise make me uncomfortable.
Feel free to PM me if you want to discuss more.