There is a +1/+1 counter on a creature you control.
You control at least one basic land.
Steps
Activate a basic land by tapping it, adding ({1} magic symbol) .
Activate Ghave's first ability by paying ({1} magic symbol) and removing a +1/+1 counter from a creature you control, creating two 1/1 Saproling creature tokens.
Activate Earthcraft by tapping a Saproling, untapping a basic land.
Activate a basic land by tapping it, adding ({1} magic symbol) .
Activate Earthcraft by tapping a Saproling, untapping a basic land.
Activate Ghave's second ability by paying ({1} magic symbol) and sacrificing a Saproling, putting two +1/+1 counters on Ghave.
Repeat.
On each other iteration, you may skip steps 4-6 to get infinite Saproling creature tokens and mana, or you may optionally get infinite +1/+1 counters and then skip the steps.