This website (https://www.buybitcoinworldwide.com/fee-calculator/) shows the approx size of transactions according to the address type, number of inputs and number of outputs and the final fee (after you set how much sat/byte you want to pay)
As you play with it you will see that the most important if you are worried about fees is to reduce the number of inputs. The best practice is to consolidate your small inputs in native segwit addresses (bc1...) when fees are low.
This way when you need to transfer bitcoins when the network is congested you will have a smaller transaction size, paying less fees.
Be careful with your privacy while doing so.