For beginners using their first cartomizer tanks, I recommend using the laser-drilled cartomizers. They are only a little more expensive than the unpunched cartos. There may be some carto punch tools on the market that are able to punch a hole without deforming the tube from round to oval-shaped, but I have not come across one yet.
This oval distortion can make it difficult to install the carto into the round hole of end caps, especially the more tighter fitting ones such as Phiniac. This can cause unneccesary stress on the end cap o-rings, which are responsible for keeping juice from leaking in the tank and are what keeps the tank fitting snugly on the carto. It just makes more sense to pay a little more for the pre-punched cartos than risk damaging your tank's o-rings, and in my experience the laser drilled holes allow just as much e-liquid to wick as a tool-punched carto.

I also highly recommend using a tank tool such as a Slap Yo Moma to further protect your tank's o-rings.
