Ply for panel, solid wood for rails and stiles. I now use Sommerfeld matched bit sets for this kind of work. The shafts are precisely matched for length so that once you set the first bit, all that follow are exactly aligned, no resetting height. You drop a half inch grommet into the collet so all bottom out at exactly the same point.
I know that there are other bit sets out there, and I haven't used them. Once I got the Sommerfeld sets, there was no point in trying anything else. Check the site Sommerfeld Tools for Wood
for information and ordering their sets. I also have their "star" shaped Sommerfelds bright yellow Easy Set Up Jig ( https://www.amazon.com/Sommerfelds-E.../dp/B00FAFIUES
), which is only $30 on Amazon, and makes setup of the first bit, adjusted for the thickness of the work piece, a breeze. Sommerfeld also makes a red version for Freud bits. Sommerfeld bit sets come in great hardwood boxes to keep them together and safe from damage.
BTW, I don't get a toaster from Sommerfeld, I am just 100% pleased with everything I've ordered from them.
Their site is here: Sommerfeld Tools for Wood
I can also highly recommend their set of videos, which cover how Marc Sommerfeld uses the router to make all kinds of interesting projects. They are clear, concise and follow a project through step by step without cutting away. Lots of close ups and hints. He was a cabinet maker before starting his tool company. You can find some of his videos on YouTube, just search for Marc Sommerfeld and you'll find them. I like having the DVDs on hand although you could save by downloading them. Have not needed customer service, but have asked them questions a couple of times and Marc himself responded.
I am sure you'll get lots of input and recommendations for bit brands and methods, but I thought I'd share my very happy experience with this brand.