There are a lot of plays/musicals on offer out there so first of I recommend doing your research. Read the reviews, watch the trailers. Find out what you really want to see. A great way of doing this is by attending West End Live which takes place once a year (it's in June. Sorry if you missed it but YouTube is your friend). It's a free event that takes over Trafalgar Square to showcase scenes from some of the greats. The best way to see what you really want to see and what's worth saving for. Not fussed on what you see but just need that cultural nourishment that only the theatre can give? Day seats tickets are your friends then. Not all theatres offer these but some hold back certain seats, often front row stalls, to sell for cheaper on the day. Hoorah!
For the tech lot (that's all of us these days, right?) there are great apps that offer discounted tickets or lotto tickets. These are for some of those in command must see plays that can't offer day seats at 10am from the box office like everyone else. Instead you're entered into a draw and informed four hours before the performance.
Whilst the shining lights of Shaftesbury Avenue sure do draw you in, they often come with the big price tags. Branch out a little further. There are plenty of theatres around that offer that same quality experience (just probably without the extravagant set).
Shakespeare's Globe and the National Theatre are both bucket list places and have great deals. Standing tickets at The Globe are £5! Yes standing for two hours can be off putting but it’s all part of the experience. If that's not you though, the National Theatre offers tickets from £15. Just make sure you book online in advance (seriously, a good few months) because those babies sell like hot cakes.
Thirsty for more? LTD often have #TicketTuesday on Twitter! Just follow (if you aren't already!) and retweet for a chance to win tickets. There are other sites that hold competitions too so always keep a look out. Now go and treat yourself. It's justifiable when you get a great offer, right?