Thimpu - Dochula pass - Punakha - Thimpu - Paro
I would suggest you to book a cab for this ride, you can easily get vehicles to directly go to punkaha from Thimpu, however then you will miss the Dochula pass which is a must to visit in Bhutan.
So early morning you start for Dochula pass, would suggest you to go on a clear day ( when there is not Fogg) so you can see Himalayan glaciers from Dochula pass which is an awesome view to have.
Dochula pass is 108 stupas which is worshipped by Bhutanese people.
You will get snacks and brkfst at Dochula pass there is a cafe over there.
After enjoying Dochula pass one will go to Punakha dzong, which is known as one of the most beautifully dzong of Bhutan, so one should not miss Punakha dzong.
Punakha dzong is created on banks of 2 rivers pochu(male) - mochu(female) river.
You will get a guide by the dzong trust. You can pay any tip to guide. There is no specific charge.
After Punakha dzong one must visit Punakha suspension bridge, which is very beautifull and engg. marvel to visit.
Return to thimpu, take a cab from Thimpu to pair, shared cabs and bus are easily available.
Reached paro, checked in hotel phunsum inn ( not so good) but cheapest one. And location of hotel is added advantage. It is 0.4 kms from Paro main market.