How do you ensure that you are not paying too much for a transaction, Talking about transaction fees, how many sat/byte do you use for transactions? Do you increase and decrease it depending on how quickly you want the transaction to be processed or how big or small the transactions value is? Do you use a fixed amount for transactions?
I don't think anyone can answer these questions with a correct answer since the cost of each transaction changes very often then you can think. Using 4 Satoshi for fees today and the transaction was fast doesn't mean it'll cost the same if you you want a faster transaction tomorrow. I don't increase my transaction fees because I want to send a larger amount.
Same fee can be used to send big amount of Bitcoin or smaller amount, all depends on how busy the network is at that point of transacting. If the network is congested then you might want to increase your fees to get a faster transaction.
Some wallets recommend fees you should use for a faster transaction and I use one of those wallets so I don't have to bother to check how congested the network is each time I want to transact.