Refineries

For Command and Conquer Gold there is a cheat code that you
can build 2 refineries for 1000 credits or it applies with
any other building or unit. You start the building and then
press r to surrender. wait about 1 min then hit cancel.
Then (if building)place the building, then start another
building and do the same by hitting r. Then hit cancel
(after 1 min) then it ought to be done! This code has been
tried several times.

Cheap commandos

How to get a commando in normal missions. Hold down
shift and click on the minigunner, you get the commando
for a minigunner's price.