Common errors and mistakes

My Geth is throwing errors and not syncing
A common cause of Geth's errors is an improper shutdown, for instance, due to power outage, or not enough time for a graceful process exit as geth writes data to disk. As a permanent fix for the latter case, you'll want to increase your systemd service's TimeoutStopSec value to at least 300.
To fix, you can resync Geth.
Running network-wide Pihole? My node is experiencing DNS issues.
By Pihole's default settings, DNS rate limiting blocks any clients with >1000 queries per 60 seconds.
To fix, either increase the queries limit value or exclude your node from Pihole's DNS.
My Ledger Nano Hardware Wallet can't deposit 32ETH for a new validator
If you encounter difficulty making the deposit transaction, enable blind signing and contract data.