Try to keep the palm of the hand in contact with the body along with the fingers. Be rhythmic, and alternate hands. A direct, focussed, compressing stroke. Thumbs, possibly braced, work well for this stroke. Be careful not to exert pressure with your fingernails if you have long fingernails.
Circular motions work well.
If you're using a table, don't lean over it - keeping your back relatively upright is best. Lean into the person you're massaging for deep strokes, rather than depending on upper arm strength. Keep your shoulders down. Keep your knees slightly bent and fluid for long gliding strokes. Be sure the room is warm enough for the person you're massaging.