Basically, as already mentioned, keep an eye on the current network congestion and use a fee estimator or a similar tool to determine a reasonable fee. Adjust the fee based on your preferences for transaction processing time. Generally, higher sat/byte fees will result in faster transaction processing times, but at a higher cost. If your wallet has the Replace-By-Fee (RBF) feature, you can use it to cancel or increase the fee of a transaction that was initially sent with low fee.