I will have around 8 days to explore Vientiane, Vang Vieng and Luang Prabang.
I plan to take a night bus from VTE to LP (a sleeper bus); Has anyone taken it? Do you think it's safe a solo female traveler?
I won't break the journey in Vang Vieng but I will make a stop on my way back to VTE (for my return flight).
Secondly, my arrival will be on first week of March - it shouldn't be a high season, right? As I want to go show for hostels/guesthouses in all those cities.
If you also have any tips for travelling in March, please also share me.
I've not taken the night buses so cant comment on that, but in March no need to book accommodation in advance.
One warning -- it will probably be very smoky due to the annual burn all the farmers do. Can be especially bad in Luang Prabang.
Smog in March is usually quite visably noticeable (red ball sunsets at 3 in the afternoon) but how much it affects breathing varies from day to day if there has been any recent local burning. I wouldn't let it determine your travel plans but just note it can be irritating especially to photographers and people with respitory problems. March is shoulder season - not as crazy as Christmas/New Year but not as dead as May or October (the two lowest months). You'll have no problem finding accommodation along the way without pre-booking. Personally I wouldn't take an overnight bus from Vientiane to Luang Prabang because the mountain pass after Vang Vieng is very hilly and twisty (potentially dangerous) and the scenery is excellent (or at least can be without the smog) so worth travelling by day. I would fly to LP for $80 then come back slow via Vang Vieng.
I'll be in Luang Prabang for only 2 nights so hopefully the smog won't be as bad as I can imagine.
I have not set a budget to fly between those cities so I'll just decide whether I'll lose a day on the road or to feel worried being on a night bus.