Any advice weather it is best to buy ticketsfor shows ahead of time or go to discount ticket booth when you arrive,thanks

Please take a look at the website for the half-price ticket booth. They have tickets on sale day of show, as well as discount tickets you can buy a week or more in advance. Also, even if they don't have the tickets you want, you can often find availability by going directly to the theatre ticket office. http://www.tkts.co.uk/

There are sometimes discounted tickets on the day of the show at the theatre ticket offices. You can see what is available at TKTS website/ www.officallondontheatre.co.uk

If there is a specific show you want to see on a specific day(s) then you should book ahead. Otherwise just go to TKTS or to the individual box offices.

Thank you!!