Step 4: SAFETY! SAFETY! SAFETY!
Look at the ground around the base of the boulder. Are there a lot of large rocks around that cannot be moved? If so, it is most likely too dangerous to climb there even if you have a safety pad to cover them. Is the boulder at the top of a steep incline? Will you roll painfully down a hill if you fall off or twist your ankle? If there is loose gravel around the base of the boulder? You can twist your ankle on that too. Is there anywhere for your spotter to stand safely and support your fall?
*Remember: always boulder with a "spotter"--a person that doesn't catch you, but rather stands behind you and supports your fall so you don't hit the ground head first.
The point being that if the ground is uneven or covered in major hazards that cannot be removed from the area, you probably don't want to climb there.