You can increase your receptivity if you feel that you are extremely helpless without the Supreme, and that with the Supreme, you are everything. This idea, this truth you can write on the tablet of your heart.
Try to feel that your inner existence and your outer existence entirely depend on the Supreme. If you can feel that He is within you to guide you, to mould you, to shape you, and at the same time to fulfil Himself in you and through you, then your receptivity will expand.
Try to feel that you are the chosen child of the Supreme just because He is utilising you, but if you are utilising yourself with your own ego and pride, then you are thousands of miles away from Him. The moment you are away from Him, you are nothing; but the moment you are one with Him with your dedication, devotion and surrender, you are everything. When you feel that you are one with Him, automatically your receptivity expands.