Child-pays-for-parent creates a new transaction spending an unconfirmed parent's output with a fee intended to encourage their combined inclusion. It adds another transaction rather than rewriting the parent's fee. Check output control, both sizes and the extra cost you bear before signing.
Replace-by-fee creates a competing transaction for an unconfirmed Bitcoin payment using overlapping inputs under applicable policies. It is not editing a number in an explorer or paying the recipient independently again. Read the replacement preview and track its relationship to the original before treating the payment as settled.
Consolidating Bitcoin outputs consumes several unspent outputs and creates fewer new ones under your control. It pays a fee now and can link previously separate sources. Compare complete present and future paths before assuming a low current rate makes consolidation worthwhile.
Coin control lets a supported wallet choose which unspent outputs fund a transaction. It can help organize sources and explain fees, but adds decisions that need review. Balance adequate funding, transaction size, change, privacy and signing capability rather than always selecting the smallest or largest outputs.
A Bitcoin transaction can show the intended recipient and another address you do not recognize. The second may be change created by your wallet, but an unfamiliar output is not automatically yours. Separate the payment, fee and remaining value, then verify ownership through your wallet's actual configuration.