Certainly, I'd love to help! Visiting Nitra, Banská Bystrica, Poprad, and Martin in Slovakia can be a great experience. Here are some travel tips to make your journey smooth:

Best Time to Visit:
The most favorable time to visit these Slovakian cities is between May and September when the weather is warm and pleasant. However, if you're interested in winter sports, December to March would be the best time to go.

Route and Accessibility:
The most convenient way to travel in Slovakia is by train or by car. Start with Bratislava, from where you can take a direct train to Nitra. From there, trains can take you to Banská Bystrica. Martin and Poprad are also easily accessible via train. Make sure to check train timings online or at the stations themselves.

Altitude and Acclimatization:
Unlike other travel destinations, the altitude in these cities is not very high. Hence, you do not need to worry about acclimatization. Nevertheless, if you plan to visit the High Tatras from Poprad, prepare for higher altitudes and carry appropriate clothing.

Accommodation and Booking:
There is a variety of accommodation options available, from budget hostels to luxury hotels. Make sure to book your stay in advance, especially during the high season or holidays.

Clothing and Essentials:
Rain can be unpredictable, so carry a light rain jacket. During the winter, heavy snowfall is common, so warm clothing is a must. Don't forget to pack comfortable walking shoes, as these cities are best explored on foot.

Health and Safety:
Stick to bottled water, as the tap water may not always be safe to drink. It's also a good idea to carry a basic first aid kit with you.

Local Etiquette and Respect:
Slovakians are usually polite and reserved. Respect their customs and traditions by dressing appropriately and behaving respectfully, especially in religious places. Learn a few basic phrases in Slovak to interact with the locals.