Great tutorial achow. One thing I want to add to it and that is, recently after updating the firmware of my Ledger Nano S to v1.3, I was able to use the Opt-In RBF (kind of) within its integrated wallet app. It has a nifty little button, which upon clicking, notifies me automatically about how much fee to increase in order to accelerate confirmation. And I guess it follows https://bitcoinfees.21.co since, most of the time it predicts the correct fee that needs to be increased before creating a new transaction. It is illustrated below: (sorry for censoring)

Step 1


Step 2


Hope this helps someone who is opting to buy a hardware wallet and not get stuck for hours in a transaction.