Certainly, visiting Jakarta, Bandung, Garut, and Yogyakarta is an enchanting experience. Here are some travel tips for your journey:

Best Time to Visit:
The best time to visit would be during the dry season from May to September. This period is ideal for sightseeing and outdoor activities.

Route and Accessibility:
You can easily reach Jakarta from many international airports. For traveling to Bandung, you can take a train, bus, or rent a car from Jakarta. To reach Garut and Yogyakarta from Bandung, you can avail of local buses, trains or flights.

Altitude and Acclimatization:
Jakarta, Bandung, Garut, Yogyakarta are all located at a relatively low altitude. So, acclimatizing your body doesn't really need to be a concern.

Accommodation and Booking:
It is advisable to book your accommodations in advance for comfort and convenience. All of these locations are tourism-friendly and offer a range of accommodation options from budget guesthouses to luxury hotels.

Clothing and Essentials:
Pack light, breathable clothes as Indonesia has a tropical climate. Don't forget your swimsuit, sunscreen, and insect repellents. A waterproof bag for electronic gadgets may come in handy.

Health and Safety:
Drink plenty of water to stay hydrated. Be cautious of street foods and make sure you have comprehensive travel insurance that covers health.

Local Etiquette and Respect:
Respect local customs and religious beliefs. Dress modestly when visiting religious sites. It's customary to take off your shoes when entering someone's home or a mosque.

Lastly, relax and enjoy the rich cultural heritage, beautiful landscapes, and the vibrant cities of Indonesia!