It's been a while since I've had a proper game plan for Legoland (before Ninjago, HH and Sky Lion opened) but here's some general good hints:
- If you are waiting by the barriers at ride opening (this was at the exits to Miniland a few years ago) head straight to Laser Raiders or Boating/Driving school. They have very low throuputs and on a busy day this will be your only chance to ride them without an unreasonably long wait.
- Ignore Viking River Splash at first. Its the first and last ride a lot of guests come across and so is always best to do around the middle of the day. Same applies to visiting the main Lego store, Hill Train and Miniland.
- Similar to the above head as far into the park early as possible and work your way back up the hill during the day. The Dragon, Sky Lion and Deep Sea will normally stay quiet for the first hour (or longer on a quiet day) but once everyone else reaches them they'll get really busy. Remember that most guests have young children with them that will want to stop at every attraction they see, so it takes the crowds a long time to get all the way into the park.
- Keep a close eye on queue time boards during the day. There are some great rides tucked away like Fairy Tale Brook that might suddenly go quiet during the day.
- Avoided the Skyrider unless it has no queue. Any change in weather can cause it to close, including "being too sunny"
- Take advantage of the shows. I'd recommend watching them if you get the chance. But even if you don't the rides near them will be quieter when the show is on and really busy once it ends. Try and get on the Heartlake express while there's a show on.
- When the crowds get too much go to Miniland and the 4D theatre, those are your escape attractions.