1) What will your hair be like? UP-STYLE or LOOSE/DOWN
UPSTYLE - It can be easy to add acessories to upstyles as the hair is more structured and will not move. Any tiara or accessory would be suitable.
LOOSE/DOWN - It can be difficult to pin a tiara onto your head as they may move or wobble. It would be better to decide on an alice band tiara, which supports itself and will be light to wear or hair clips/grips.
2) Think of your face shape?
People have different shaped faces and a tiara that you like may not suit your face shape.
ROUND FACE SHAPE - Inverted V-shape tiara or a tiara with height will flatter the face.
OVAL FACE SHAPE - Most style of tiara / hair accessory would be suitable.
LONG FACE SHAPE - Short tiaras or hair accessories would compliment the face shape best.
3) Colour and Materials?
Choose a tiara that matches the wedding dress, for example pearls and crystals or for a prom dress, a matching colour to compliment your dress.