A good thing to do, is when you start the day, write down the amount of settled cash at the beginning of the day before you do any trades. You can open and close as many trades as you like that day, no PDT, as long as you don't exceed that amount.
Say your settled funds are $10K, you can do 20 round trip trades buying and selling an $5 Apple call or put. And then do the exact same thing the next day.
And... say you do that. Your last trade of the day after you've done those 20 ----- you can still buy a position to hold overnight. For example you could buy all 20 Apple $5 calls for $10K and then hold overnight.
The next day however you will have zero settled funds. If you sell, the $10K is available to open another position, BUT you must hold that one overnight too. If you just close the position and take the day off, the $10K will settle the next day and you can do your 20 round trip trades all over again.
And it works the same way with "sell to open", ie sell a $5 put and buy it back 20X in one day. The next day you can do the same thing because the funds you received selling will be settled in your account.