Sure, here are some travel tips for your visit to Brasov, Sighisoara, and Alba Iulia in Romania:

Best Time to Visit:
The best time to visit these Romanian cities is during late spring (May and June) or early autumn (September and October) when the weather is mild. However, if you enjoy winter sports, visiting Brasov in winter (December to February) is a good idea due to its proximity to popular ski resorts.

Route and Accessibility:
The best way to travel between these cities is by train or car. Start from Bucharest, you can get to Brasov by train in about 2.5 - 3 hours. Trains from Brasov to Sighisoara typically take around 2.5 hours, and traveling from Sighisoara to Alba Iulia takes roughly 1.5 hours by train.

Altitude and Acclimatization:
The cities are situated at a comfortable altitude with Brasov at 625m, Sighisoara at 429m, and Alba Iulia at 215m. So, issues related to acclimatization are less likely unless you are planning for a hiking trip in the Carpathian Mountains nearby.

Accommodation and Booking:
It's advised to book your accommodation in advance. You will find a range of accommodation options available from budget hostels to luxury hotels. Remember, the summer months (June to August) can be particularly busy.

Clothing and Essentials:
Carry clothing according to the season. If you are visiting in winter, warm clothing (including hats, gloves, and scarves) is essential. Waterproof shoes or boots are also recommended. Don't forget to pack a good quality camera to capture the stunning architecture and landscapes.

Health and Safety:
Romania is generally a safe country. However, like any other place, it's always a good idea to be cautious about your surroundings and maintain good personal safety standards. For health emergencies, make sure you have relevant travel insurance.

Local Etiquette and Respect:
Romanians appreciate polite and respectful behavior. While visiting churches or other religious sites, proper decorum and dress are expected. Monasteries, in particular, often require modest dress. Try to learn a few basic Romanian phrases, it'll be appreciated by the locals.