If it it newly planted try not to let it fruit during the first year. When it does fruit thin them out no more than 2-3 per spur, otherwise you may get no fruit next year. In late July or early August take out the growths beyond the developing fruit back to 3 leaf axils to allow fruit to enlarge. In february before growth begins prune out any overlong shoots back to 3 leaf axils. Limit height, if it is getting too tall, and cut off any extra shoots low down to stop branching off. Then grease banding is easier. Miniature trees are often very small when young and very variable in rootstock vigour. You have to see if rampant or or a bit weak and slow.