How do I pay more in fees when the BTC has left the wallet
If you used Armory 0.96.5 to create the transaction, the RBF (Replace By Fee) flag would be on by default, meaning you can "respend" your inputs as long as the original transaction has not been included in a block. The transaction would show in a teal line in the lobby's tx ledger, and you would be able to right click it and pick the RBF option, which will let you update the fee.
If you still have coins in the wallet, you can also choose to CPFP (Child Pays For Parent). This is a situation where you create a follow up transaction that spends from the unconfirmed tx (typically your change within that tx) and pays a high fee. This incentivizes the miners to confirm the parent tx (low fee) to get the fees on the child (high fee follow up). In essence, it "pulls" the first transaction along.
To CPFP in Armory, you need to set the user mode to expert, then in the "Send" dialog, the "Coin Control" button will appear. In there you can pick those outputs that are eligible for CPFP (they're listed in their own subtree) and create a transaction that "pulls" them in.
To summarize, you can:
- "respend" the inputs if RBF was enabled at tx creation
- "pull" the tx with a high fee child if it has a change output
