Should I bring cash or use ATMs?

Use ATMs. Bring a debit card with no foreign transaction fees and take out the maximum amount allowed per transaction to minimize the flat ATM fees charged by local banks.

Is it cheaper to book internal flights in advance?

Generally, yes. Flights booked 2-3 weeks out are significantly cheaper than last-minute bookings. Use budget carriers like AirAsia or VietJet.

How to budget for a two-month trip to Southeast Asia

Budget $2,000 to $2,500 USD total for a comfortable mid-range two-month trip, excluding long-haul flights. This covers private rooms, daily street food, regional transport, and occasional tours.

Calculate your fixed daily burn rate. Allocate $30 per day for accommodation (private guesthouses), $20 for food, and $10 for incidentals like laundry, SIM cards, and coffee. This $60/day base covers the bare necessities.
Add a 20% 'adventure fund'. Set aside an extra $12 per day for activities. This covers entrance fees for temples, one-off experiences like scuba diving in Thailand or a Ha Long Bay cruise in Vietnam, and regional transport.
Factor in visa costs. Budget $150 total for visas. Depending on your nationality, countries like Vietnam, Cambodia, and Indonesia require paid entry visas ranging from $25 to $50 each.
Account for regional transport jumps. Budget $300 total for 'unexpected' movement. This covers the occasional last-minute flight between countries or long-distance train/bus upgrades.

Should I bring cash or use ATMs?: Use ATMs. Bring a debit card with no foreign transaction fees and take out the maximum amount allowed per transaction to minimize the flat ATM fees charged by local banks.
Is it cheaper to book internal flights in advance?: Generally, yes. Flights booked 2-3 weeks out are significantly cheaper than last-minute bookings. Use budget carriers like AirAsia or VietJet.