Handing in my notice

[Borogoves]

I need to resign from my job. My line manager is great and it's going to cause him a bit of a logistical nightmare covering my work. What's the most courteous way to resign? I only see him once a quarter so can't do face to face as I would prefer. Do I phone him and let him know I'm resigning then follow up with a letter? I rarely get straight through to him on the phone so would probably have to leave a voicemail. Should I email him to let him know and attach a resignation letter in a word doc with a hard copy to follow? It will come as a bit of a shock to him as I have recently taken on extra responsibilities so want to do this in as nice a way as possible!

[WhereInTheWorldToNext]

Can you schedule a call with him and tell him then - presumably that will forwarn him that there is so
Etching specific you want to discuss