I use velcro on all my RX and batteries.
If the fuselage is sheeted I put in adhesive backed velcro hooks in the bottom or top depending on if it is high or low wing and install the hooks on the RX or battery over a layer of foam padding,
The velcro can be bought at any sewing supply store.
If the Fuselage is not sheeted you can put in a piece of ply across the ribs and put the velcro on that.
What I like about this method:
It is simple and clean.
RX and Battery can be easily moved around to balance the model.
RX and battery can be easily moved from plane to plane if you want.