If you want to go to Savannakhet it is easy to get there by buss. You take the buss from the station at Big C. If you have a motorbike it is good to park it in the garage next to the buss station since the trip will need to you spend a night in Laos. The bike place charges 10 bath a day. If you want your visa the following day in Savannakhet you need to hand in the paperwork to the embassy before 11 AM. This requires that you leave the buss station with the 6.30 AM buss and that is no guarantee that you make it.
Anyway, you need 3 passport photos with you (one for Laos immigration and two for the visa) and a photocopy of your passport. You can get the two passport photos needed for the visa and the photocopy outside the embassy, but make sure you bring a photo for the Laos boarder.
In order to get to Savannakhet you take the buss from the Ubon buss station to Mukhdahan, it cost 135 bath. In Mukdahan you get of at the buss station and change to an international buss that drives across the border. The international buss cost 45 bath and during that trip you need to get the Laos visa for 1500 bath. You will most likely have to pay some small administrative fees here.
The joy of boarder crossing
When you get across the boarder you can just get a tuktuk to the embassy. If you hand in the paperwork before 11 AM, you get the visa the following day after 2 PM.
The worlds slowest tuktuk
Thai embassy
And now for the kicker, Savannakhet is painfully boring, there is nothing to do in the boring backwater town. There is two restaurants that serve eatable foods, an internet cafe and a hotel. I stayed at Hotel Mekong, 2 people in a 2 bed room costing a total 320 bath per night. It is also located very close to the embassy.
Hotel Mekong
So what to do in Savannakhet at 11 AM in the morning?