I want to get into writing music more. I want to be able to write good songs and riffs and well, write music. Whats your process when you write? Do you start choosing a key, (btw, how the heck do you guys know what key you want?!) and then choose chordprogressions or how do you do it?

Please help a newbiewriter out

And btw, do you got some tips on songwriting that might come in handy?

Im into metal like metallica, maiden, megadeth if that helps.
the only real reason to 'choose' a specific key i've ever encountered is to favour the vocals, i.e. a step down or a step up here n there, but generally i dont start like that, the way i begin writing songs is to think about a chord, think about a chord or two to play off it, play around with riffs from there, and then i have the key like that.

Almost everything is a variable, there is are infinite ways of doing it, you've gotta play what you're into in the moment, whatever tempo or riffs you come out with, the minute you try to write someone else's songs you'll get nowhere
Read the forum rules, then post your song here. People give you feedback, and over time, you will get better if you pay attention to what's being said.

But first, read the forum rules.