Best way to buy theatre tickets in London?

I often buy at the Leicester Square 1/2 price ticket booth. Usually end up in the stalls which is fine.

I also use https://officiallondontheatre.com/theatre-tickets/

London theatre is always fun. Its the ice cream cups at intermision.

Enjoy!

EDIT: if The Play That Goes Wrong is still playing try to get tickets. Funny and well done. Witness for the Prosecution if still on at County Hall is most enjoyable. Its set in a real courtroom.

Yes buy tickets online. You can just buy them direct from the theatre that you want to go to. They all do online sales.

If there's something running that sounds unmissable to you, definitely get your tickets in advance; it might sell out in the interim. I've found that ticket availability often dries up a few days before the performance; I've missed some things I wanted to see because I dallied. If you just want the theatre experience and are willing to settle for one of the handful of shows that are deeply discounted when you get to London, you can probably wait. (I don't recommend that, myself.)

The TheatreMonkey website is really useful in detailing the seating conditions in each theatre (https://www.theatremonkey.com/venues) so you have the information needed to make a smart ticket selection. There's a link to a list of shows here: https://www.theatremonkey.com/shows

Since we never know whether we’ll make it to the theatre, we too just go to the TKTS booth in Leicester Square. Oftentimes, the theatre is a last minute or day of decision.

We are also going to be in London in October. Looking at the show schedule, has anyone seen SIX? Recommended?

The link Claudia posts above is the official online version of the physical ticket booth at Leicester Square. The tickets appear daily after midnight London time and disappear during the day as they sell out. We used this method from the US to buy tickets last summer for plays and musicals we wanted to see. However we wanted to see Hamilton in London, have seen it here, but there were never tickets at the discounted official site so we bought Hamilton tickets online, directly from the box office before we went.

https://officiallondontheatre.com/tkts/

@Tammy,
SIX is creative, colorful, and loud! Recommended. I saw it in late spring last year and may take friends to see it this May. We always try to sit in stalls, but were a little too close for this one, probably about fourth row. Got blasted in the face by onstage lights a few times too many. It's a fun show!