Excellent thread.
While folks based in/around Delhi seem to have unlimited options closeby & can spontaneously head off in any direction, I believe that for folks based in/around Mumbai, we definitely have to plan a bit more in advance.
Here are some recommendations based on my past trips. I plan to write travelogues in due time (as I joined only this week):
1) Explore "tried & tested" Rajasthan:
Mumbai - Udaipur (1 day drive, 2-3 days to explore around and in city. Must visit Ranakpur temple which is couple of hours away)
Udaipur - Jodhpur (half day easy drive, 2 days to explore at a min. My fav city in Rajasthan. Lip-smacking food and easy to get lost in the old city walking about)
Jodhpur - Bikaner (half day easy drive, 1 day to explore Bikaner, and 1 day at Gajner Palace Heritage hotel which is 20 kms before you reach Bikaner. a real gem)
Bikaner - Jaisalmer (half day easy drive, and you can easily spend 3 days with Jaisalmer as the base)
Jaisalmer - Mount Abu ( 1 day drive, and 2 days at min in Mt Abu. I am a big fan of Dilwara temples)
Mount Abu - Mumbai ( 1 day drive, a little long)
Easily a 2 week trip, and you can add/subtract based on what you like. I have done Rajasthan couple of times now and I still want to go back again
2) Southern & Eastern Madhya Pradesh:
Parts of this trip were recently traveled (winter 2020), though it was part of a longer overall trip. Others were done separately, but am stitching them together based on overall experience. Furthermore, I am planning a trip to Maheshwar/Omkareshwar/Bhopal next month, so this is how i would go about it (and in some part, done it already):
Mumbai - Maheshwar (1 day drive, atleast 1 or 2 days to see around. you can do Mandu which is closeby as well, as is Omkareshwar, or that can be done in the return)
Maheshwar - Indore (2-3 hours drive, and 1 or 2 days to checkout Indore. What is more imp is the nights in Indore to try the Chappan Dukkan street food magic!)
Indore - Ujjain - Dewas- Bhopal (Start early, and cover the temples of Ujjain, Dewas and reach Bhopal in 1 day). Spend 1 max 2 days exploring Bhopal
Bhopal - Khajuraho (1 day drive. I did it recently and its largely good roads, though its 2 lane highway mostly). Atleast 2 days in and around Khajuraho. Loved it!
Khajuraho - Jabalpur (1 day drive) and enjoy Bhedaghat.
From Jabalpur, many options come up, depending upon what you enjoy:
visit Kanha Tiger Reserve
visit Pachmarhi hill station and tiger reserve
visit Pench national park
Depending upon where you go, you can return to Omkareshwar or Indore and from there make way back to Mumbai. And if you hit Pench, then you can return via Nagpur route too.
3) Northern Maharastra:
This is a trip i have done 3-4 times in multiple iterations. Sharing below the latest trip from Nov 2019.
Day 1: Mumbai to Nasik, visit key places and rest in Sula Vineyards.
Day 2: Explore Sula & surrounding lake in morning/afternoon and post lunch, we reached Shirdi (Another option is to go to Saputara)
Day 3: Shirdi Darshan and other temples if it interest you, though we still managed to reach Aurangabad by afternoon/evening.
Day 4: Ellora Caves & Devgiri fort (also known as Daulatabad). Ellora itself needs atleast half a day. And Devgiri fort is huge. Your stamina determines how much you want to explore!
Day 5: Aurangabad city caves, Mini-Taj Mahal etc. Relax a bit. Some very nice restaurants in Aurangabad this time when I visited vs many years back
Day 6: Ajanta Caves. The roads were fully under construction in 2019 Nov, so it was a nightmare. Took me 3.5 hours to cover 90 kms (one way). But the Ajanta Caves themselves are a sight to behold. Hopefully roads are ready by now.
Day 7: Drive to Paithan (i am a history buff, and it was capital of Satvahana Dynasty), Enjoy the Nath Sagar (Godavari Reservoir) and reach Ahmednagar at night. I stayed in Ahmednagar and saw some historical places due to my uncle being in Defence. You can skip if its not interesting enough for you
Day 8: Reach Bhimashankar and can spend a day/night, or travel along and reach Mumbai/Lonavala depending upon your preferences
My trip was 8 days and it was not taxing at all.
Hope this helps. Just some ideas based on my travels! happy to get feedback based on other's experiences
Cheers!