- Obviously the very first thing I'll suggest is to read as many of the old myths and stories as you can, preferably as close to the originals as possible. The re-tellings are nice, like Lady Gregory's Gods and Fighting Men, but they often take liberties with the stories and change details that make big differences. You can find many of the older stories at Mary Jones Celtic Literature Collective and the stories which feature the Morrigan especially include the Cath Mag Tuired Cunga, Cath Maige Tuired, Lebor Gabala Erenn, and many of the tales in the Ulster Cycle. Beyond that there are several modern authors who have written in detail about the Morrigan that are worth reading - my favorite is Angelique Gulermovich Epstien's "War Goddess: The Morrigan and Her Germano-Celtic Counterparts".
- If possible you should go and visit the places the stories happen in. Smell the air, touch the earth, feel the wind. Stand in the places that the Morrigan herself is said to have stood in, is still said to stand in, like Uaimh na gCat, and feel her presence there. If that's not possible then quiet meditation wherever you are is good, but I am one of those pesky people who thinks going to Ireland should be a goal for those who follow herself. Even if its a once in a lifetime goal. Until then of course you can do your best to feel connected to the locations of the myths, to the places where the Gods are invested in the land itself by learning as much as possible about them.
- Set up a small shrine to her. I'm a fan of statues and artwork and there is a huge amount to choose from for the Morrigan. My favorite statue is Dryad Design's Morrigan, which I bought and then painted myself. There are also a variety of great art prints out there. Beyond that personalize as you see fit. I like shrines because they provide a quiet place to sit and visually reflect on the Gods, as well as being a place to light candles, burn incense, and make offerings.
- Speaking of making offerings. A good way to establish a connection to any deity is to begin making offerings to them. For the Morrigan my own preferences are milk (or cream), whiskey, or bread, although I often offer different things spontaneously as well if I feel drawn to.
- Pray. This tends to be less popular with some people but it really is a good way to connect. Whatever works best for you, whether that's formal memorized prayers or spontaneous speaking from the heart, the point is just to reach out and speak to the Gods.
- Music. I really love music as a vehicle for altered states, trancework, and just plain feeling more strongly connected to something. When it comes to the Morrigan my personal favorites are Omnia's Morrigan, Darkest Era's The Morrigan, Heather Dale's The Morrigan, and Cruachan's Brown Bull of Cooley and The Morrigan's Call.
- My final suggestion would be to get a piece of jewelry that represents or symbolizes the Morrigan for you, that you can wear to help you feel more connected to her. This is largely a psychological thing for the person, a physical token to touch when you need that tactile reminder. Over time though it can become sacred in its own right as its blessed or empowered.
So there you go, a short basic list but one that I find effective. Many or most of these may just be common sense but I have found they are all helpful, especially if done regularly. Having a regular spiritual practice is vital in my opinion and this is how I incorporate the Morrigan into that.