The best way I would strengthen a bond of a diety is to give her, her "corresponding" offerings. Note the word Corresponding, Every diety have their own correspondences, now if you don't know what correspondences are, they are the "Things or objects that the diety corresponds with". A good example of correspondences would be a basketball player playing with a volleyball, now obviously the basketball player is used to play with a basketball than a volleyball since the player corresponds with the basketball. If you give a basketball player a volleyball, his "skill" would degrade because the volleyball does not correspond with him. I believe the offerings you are giving are just "anything of the mat" and that is ok, but to really give it some more "oomph" I would recommend using Aphrodite's correspondences which I will list below.
A good way to strengthen your relationship with a diety too is to meditate about it. Visualize yourself in your mind, visualize yourself giving gifts for her if you don't have the "Material" substance, and who knows she might contact you back. Maybe a short prayer would work too, from the heart. I would urge you to construct a ritual using her correspondences (be creative), a prayer, and a brief meditation. Although this is simple, it is very effective and it helps a lot. Namaste!