If you sign up to MySephora, you can get choose between a free birthday gift, £5 voucher, or a charity donation for your birthday. The gifts depend on which rewards tier you're in (Bronze, Silver or Gold) and are based on how much you've shopped at Sephora in the last year. Some examples of current gifts include:
Bronze Tier
Pixi Glow Tonic, 15ml
Sol de Janeiro Bum Bum Cream, 25ml
Dermalogica Daily Superfoliant, 4g
Silver Tier
Shiseido Essential Energy, 15ml
Sol de Janeiro Cheirosa 62 Mist, 30ml
Elemis Pro-Collagen Cleansing Balm, 20g
Gold Tier
Byoma Brightening Kit
Fenty Beauty Gloss Bomb Hot Chocolit
Shiseido Ultimune, 10ml
You need to make sure you're signed up to MySephora at least 24 hours before your birthday, and you have one month to redeem your free gift/reward. See full T&Cs.
Use them
If you answer 'NO' to any of the following questions, don't buy.
Are you
Will I use it?
Is it worth it?
Are you
Do I need it?
Can I afford it?