Italy's west coast - recommendations and reservations?

August is very busy! To find an ok hotel with a reasonable price for august vacations, people make reservations around February. I say it's way too risky!

There will be no people hawking at stations except for major tourist destinations like Rome or Florence.

Will you have a car for your coastal visit?

With a car I have a plethora of great places to recommend. Without a car, and relying solely on trains, you will be severely restricted to where you can go, since the coastal train runs actually a bit inland for the most part. There are stations on the coast, for example (from South to North): Santa Marinella, San Vincenzo, Rosignano, Castiglioncello, Viareggio. But all other towns the train touches are not exactly on the shore. There are buses of course.

Without a car you will be somewhat stuck to the town where you decide to stay, since buses are not that frequent.

Other than the towns mentioned above, the best sea is in the Maremma Area (roughly near the Mt. Argentario peninsula). Porto Santo Stefano, Porto Ercole, Talamone, Follonica, and any place in that proximity is good, but the best beaches are hard to find without a car. August is also very busy, so a car would give you more flexibility on accommodations that will be certainly hard to find in August.

If you can rent a car in Rome and return it for example in Pisa at the airport, it would be best.
Check the website below on Maremma.

https://www.tuttomaremma.com/en/

Please book your hotels or apartments in advance so you are sure to enjoy your vacation.

Consider Gaeta if you like quaint villages with beaches. It's near Rome.
You could visit Lucca for the charming but less crowded Tuscany vibes.
There are many other towns like Pitigliano, Montepulciano and Volterra worth a visit.

bookmarking--will come back when you reply on the car or no car issue. I love this area!
How long will you be in Rome, CT, Pisa, and Venice?

You absolutely need reservations on the coast in August.

We are traveling by train. And thank you all - I'm booking places now!

The area Roberto mentioned has some limited bus service, say if you took the train to Orbetello station, from there you can take a bus to one of the towns on the promontory or to flat, old town Orbetello. There are ferry trips and beaches that are reachable by bike (*ebike rentals have really improved, so if you feel a regular bike might be insufficient, take heart). The beaches at Feniglia are natural and reachable by bike. I don't know what this area is like in August though--certainly filled!