Choosing the right crystals to meditate with is very important. You need to consider what your goals are from meditating. I.E, what you are hoping to achieve from your session and what clarity you are looking for. It is believed that different crystals hold certain benefits in their energy/vibrations.
Depending on what sort of vibe you're looking for, you can pick your crystals by colour to match the chakras. This can be helpful, as different colours often associate with different chakras (most of the time) This gives you an as easy map to find stones that can help support your meditation goals.
Another way to pick what crystal to mediate with is by choosing the crystals intuitively. This means you skip the research/guidance altogether and simply go with whatever crystals feel right (what you are drawn to). The more you practice meditation and trusting your own intuition, you will be more in tune with your emotional states and changes in response to a crystal's energy.
No matter what method you use to pick your crystals, make sure to always cleanse them first. (I will cover how to cleanse your crystals further in this blog).