Raspberry Spotify (Spocon, Raspotify) cheatsheet

Connect to a bluetooth speaker

sudo bluetoothctl
power on
pairable on
agent on
default-agent
scan on
pair xx:xx:xx:xx:xx:xx
trust xx:xx:xx:xx:xx:xx
exit

BT-Audio for audio output
https://github.com/bablokb/pi-btaudio
Remember to disable the reconnect daemon 
sudo systemctl disable pi-btaudio.service

Alternative to Raspotifty - gracefully handles disconnects
https://github.com/spocon/spocon
That uses
https://github.com/librespot-org/librespot-java
Config changes for Spocon
sudo  vim /opt/spocon/config.toml 

Disalbe logs system-wide (protect SD card)
sudo vim /etc/rsyslog.conf

Check logs
journalctl -u raspotify.service -f
journalctl -u spocon.service -f

Check wifi standby and disable 
iw wlan0 get power_save

Disable power saving one time with:
iw wlan0 set power_save off

Or disable it permanently with a udev rule. My example for Arch Linux:
file: /etc/udev/rules.d/81-wifi-powersave.rules:
ACTION=="add", SUBSYSTEM=="net", KERNEL=="wl*", RUN+="/usr/bin/iw dev $name set power_save off"