MEDITATION.
Or you can just sit outside or at the park.. Wherever you are comfortable and let your mind go. Pay attention to thoughts. Thoughts from angels and guides would bring peace or joy. Anything that brings worry or trouble is your ego. You also have to be open to feelings brought or sensations. But you have to sorta "clear out the clutter" in your mind so that you can hear them clearly and meditation of just sitting with a quiet and calm mind will help!

Also.. Pay attention to any visual images to come up in your mind, or your dreams, or sensations in your body, to dreams, or signs/coincendances......

There could be various ways they try and communicate with you and so you have to be open. TELL THEM you want to commuincate with them. You can even light a white candle for them when you do so. The vibration of the candle will be helpful to you.

Essentially, you have to learn how to LISTEN. And let the information flow in how it will because imagine if you on their side.. Trying to send messages or signals.. You would have to use any tricks or visuals you could. Perhaps maybe through dreams, feelings, or sending signs, etc. So be open and send out the intent! TELL THEM!