I use the bark grafting technique to graft to larger limbs of established trees. You can only do this grafting when the sap is starting to flow and the bark will "slip" away from the wood of the tree. I make a downward cut and slowly peel the bark back.
I coat the graft with wax from a toilet bowl gasket to keep the graft from drying out. It works just as well as the grafting wax you can buy and is much cheaper.
It won't be long before the apple blossoms are open.
The rain has stopped for now so I'm going out to enjoy Spring.