Getting matched for foundation somewhere, figuring out your undertones, and if you lean more cool or warm will help the most. For example my skin is very yellow, which most people assume is very warm, but I am technically on the coolest side of yellow so I look better in mauves, plums, and cool berries than oranges, peaches, corals, etc.

A deep mauve color for me is basically MLBB (My lips but better).

If you lean cool you'll probably notice lip products, foundations, and blush tends to pull more orange, brown, or yellow on you than you'd like. If you lean warm you might notice those things pulling more purple or gray than you'd like.

Here are some terms you should know

Matte - These are flat-looking colors that look and feel dry to the touch. Pros are they tend to be longer-lasting and transfer less than other lip products, but cons are that they can be very drying on the lips and uncomfortable. Cream - These tend to be less drying and sometimes even hydrating. They have a bit of a shine to them. You will likely have to reapply throughout the day and they will transfer onto anything that touches your lips, but they will also be more comfortable. Satin - Something between cream and a matte. If matte products dry your lips out too much but you want something longer lasting than a cream/gloss product try satin lip products. Demi-matte - Between Satin and Matte.