How powerful is your bandsaw? HP makes a lot of difference.
If you are sawing staves, or belly splits then you need to steer the timber freehand to saw straight. Also you are dealing with no really flat and stable surface that will balance safely on the saw's table, so that makes it much trickier than if using flat, straight lumber. Go slow, don't force it, let the blade cut at its own pace.
A fresh sharp blade makes a lot of difference. If its dull then any sawing will be extremely difficult, and probably inaccurate.