Absolutely, these Tunisian cities have a lot to offer. Here are some travel tips for your journey:

Best Time to Visit:
The best time to visit Tunis, Sfax, and Kairouan is during spring (April to June) and autumn (September and October) when the weather is pleasantly warm. Summers can be intensely hot, especially in the inland city of Kairouan.

Route and Accessibility:
Tunis, the capital, is well-connected with international flights. From Tunis, you can take a train or bus to Kairouan and Sfax. There are also options for domestic flights if you prefer.

Altitude and Acclimatization:
These cities are near sea level, so acclimatization is not typically an issue. However, in summer, the temperatures can rise significantly, so it's crucial to stay hydrated and avoid excessive sun exposure.

Accommodation and Booking:
There is a range of accommodations in these cities, from luxury hotels to budget guest houses. Booking in advance is suggested, especially during peak tourist season.

Clothing and Essentials:
In consideration of the country's predominantly Muslim culture, it is advisable to pack modest clothing. Sunscreen, a hat and sunglasses are essential due to the sunny weather. Also, pack a good quality pair of walking shoes for sightseeing across these cities.

Health and Safety:
It's advisable to drink bottled water and avoid raw food to prevent any potential stomach issues. Always ensure that your travel insurance covers any eventualities.

Local Etiquette and Respect:
Tunisia is a Muslim country, so do respect local customs and traditions. During Ramadan, be discreet when eating or drinking in public during daylight hours. When visiting mosques, women are expected to cover their hair, and both men and women should wear clothing that covers their knees and shoulders.