By popular demand, I will write about our trip to London and Amsterdam after all. Unlike my usual style, not in detail, for various reasons: there is no time, plus there is no need to post some things on the internet. Also I am sick, so the story will inevitably be jumbled, and with tyops.
The first part will be about planning and tickets. For keeping track, google docs+google calendar were used. In the calendar, there was a plan for each day of what we'd see. The plan didn't exactly pan out, but we did manage to see some things.
I bought many tickets electronically, entered them into a spreadsheet. Then everything was printed out in three copies, for each of the participants. Overall the system is convenient, I'll keep using it. I frequently used the site https://www.amsterdam.info/
The tickets to Amsterdam were bought from airBaltic, from London - WizzAir. To estimate prices the site skyscanner.net is handy, for buying it's better to use the companies' sites. Only a few low-costers fly out of Riga - meaning cheap point-to-point type airlines, and you can check them all. (WizzAir, RyanAir, Norwegian, sometimes AirBaltic has good prices).
Also, right now there is a trendy Russian site momondo.com, which pulls data from a bunch of other systems, but doesn't let you buy things itself. It seemingly doesn't account for low-costers.
Overall, I'm already pretty good at figuring out the options for flying from the surrounding areas. Here is a brief guide for you.
Around Daugavpils (and Riga) there are the following airports, which are realistic to get to for a reasonable price and time, and from where you can find decent flights.
Easy to get to:
1. RIX - Riga's. We got lucky, our airport is popular and comparatively a lot of carriers fly from there.
2. KUN - Kaunas, that's where the Ryanair base is located, and it flies to many places from there.
3. VNO - Vilnius. Not particularly useful, but there could be a cheap flight from there too, for example Scandinavian Airlines to Iceland
Harder to get to:
4. HEL, Helsinki. A bus from Riga to Tallinn, a ferry from there, and from there a local bus to the airport (20 km or so). The price of the cheapest bus to Tallin - 14 ls round trip, the ferry is 40 euros one way.
5. ARN, Stockholm. The ferry https://www.tallink.lv/lv/ from Riga, the price is not small, around 70-100 Ls one way for the cheapest option, so the savings are questionable.
From Amsterdam to London you can get by ferry or train, everything is described in detail at https://www.seat61.com/. I bought a Rail&Sail ticket for the ferry and train right away, it works as written on the site. I had to buy it in Dutch, but it's not as scary as it sounds. The only catch - you have to buy the ticket at the train station in Amserdam RIGHT AWAY to the port from which the ferry departs, that is Hook Of Holland, otherwise you won't get your money back.
The price of the plane ticket to Amsterdam was only 33 lats, from London - 42 lats (would have been 7 lats cheaper, had we bought the ticket a day earlier), the price of the train+ferry ticket from Amsterdam to London - around 55 lats. All prices are per person.
Planning using the internet is convenient enough, Google is your best friend regarding museums, galleries, beautiful views and stuff. The only thing that's better to look up separately - concerts, that's on last.fm.
I'll probably write about other things and event tickets later, when it comes up.