Should I bring a sleeping bag?

No. Hostels provide linens, and it is usually too hot for a sleeping bag. A silk or cotton sleep liner is useful if you are concerned about cleanliness.

Is it better to wear hiking boots?

Only if you have specific trekking plans. Otherwise, they are too heavy and bulky. A comfortable pair of trail runners will serve you better for walking through cities and light trails.

Laundry services are everywhere in Asia. You pay by the kilo, usually costing about 1-2 USD per load, and you get your clothes back cleaned and folded within 24 hours.

How to pack for backpacking Asia

Pack for one week of laundry, not for the duration of your trip, and prioritize lightweight, breathable fabrics. Limit your total bag weight to 10kg (22lbs) so you can carry it on all budget airlines and maneuver through crowded public transport.

Choose the right pack. Use a 40L to 45L travel backpack. Do not use a hiking bag with a rigid external frame; you need a bag that opens like a suitcase so you can reach your items without dumping everything out.
Use compression cubes. Pack clothes into three packing cubes: one for tops, one for bottoms, and one for undergarments. Roll your clothes tightly before putting them in the cubes to save 30% more space.
Build a modular wardrobe. Pack 5 t-shirts, 2 pairs of lightweight trousers or shorts, and 1 light rain jacket. Bring fabrics like merino wool or polyester blends that dry overnight; cotton takes too long to dry in humid climates.
Consolidate electronics. Carry one universal travel adapter with multiple USB ports. Leave the heavy laptop at home unless you are working; a tablet or smartphone is sufficient for booking transport and keeping in touch.
Prepare a small medical kit. Pack a small pouch with Imodium (anti-diarrheal), oral rehydration salts, antiseptic wipes, and a few band-aids. Keep your prescription medications in their original bottles with a copy of your prescription.

Should I bring a sleeping bag?: No. Hostels provide linens, and it is usually too hot for a sleeping bag. A silk or cotton sleep liner is useful if you are concerned about cleanliness.
Is it better to wear hiking boots?: Only if you have specific trekking plans. Otherwise, they are too heavy and bulky. A comfortable pair of trail runners will serve you better for walking through cities and light trails.
How do I do laundry?: Laundry services are everywhere in Asia. You pay by the kilo, usually costing about 1-2 USD per load, and you get your clothes back cleaned and folded within 24 hours.