Usually when you create a wallet all your address types are the same meaning all your inputs are for example P2WPKH not a combination. Your outputs can be of any type since payment is usually to others and other people use different wallets. For example a gambling site may only produce P2PKH addresses.
One method blockchain analyzers use to find the "change address" is to find these differences. Meaning if your input is from P2WPKH address and your outputs 1/2 is P2SH and 2/2 is P2WPKH there is a good chance that output #2 is your change.
The default wallet/address type Electrum and bitcoin core create right now is P2WPKH (ie. with version 0 witness program).
As for other factors, default transaction version that majority of wallets use is 2.
Locktime is similarly the best block height in most wallets, I know Electrum uses your best block height I'm not sure about core since it was changed a couple of times but it used to deduct a random number smaller than 100 from the block height "sometimes".
I believe the default setting of Electrum is to enable RBF so sequences will be lower than max and by default it seems to be setting them to 0xfffffffd. Obviously if you don't enable RBF it will be max.
