trezor – What is the most frictionless way to put Bitcoin into my wallet?

I’m a complete noob to cryptocurrencies (I bought my first few mBTC a month ago) and the proud owner of a new Trezor One hardware wallet. I would like to ask what is the most direct and seamless way to get bitcoins to my Trezor.

I already set up my wallet and made a transfer to my first wallet, which was successful. But I had to sign up first, purchase coins through an independent reserve, and then transfer them to my wallet address. Independent Reserve charged me when I paid dollars into their account (paid $500, they credited me about $497), and when I transferred from that exchange to my trezor they charged me a few satoshis . It looks very complicated.

Is there a more direct way without going through these additional transfers?

Related, the trezor one family (I’m using the Linux Deb version) has an address with a QR code. Is it safe to keep a copy of this QR code on your phone and flash it to a Bitcoin ATM (or share it with all senders via WhatsApp) to receive Bitcoin? Will the ATM send directly to my Trezor One?

Sorry for asking a stupid question. We’re trying to find the safest and most cost-effective ways to navigate the landscape.