Top is the handiest.
You can add extra dimensions to your bucket by adding 5 total. Weld 3 across the top. One in the middle, one at each end.
Weld the remaining 2 on the backside of the bucket, one at each end.
You will usually use the one on top in the middle. When you pick up something long, use the two on top at each end.
When you need to carry something flat like a gate or panel, use the two outside tops and the two outside backs.