Sienna Miller splashes in Cancun, Mexico

Sienna Miller splashes about in Cancun!

Sienna Miller gives us some ultimate bikini shopping tips on her current holiday in Mexico!

Lesson 1 - We're all over the mix and match.  Buy co-ordinating colours in your favourite bikini shapes and mix it up so you've got loads of bikini wearing options for your dream holiday!

Lesson 2 - Buy the right size!  Sienna seems to be struggling to keep her bandeau up in the surf - loose bandeau's and waves are not a match made in heaven.

Lesson 3 - Don't stick to black - grey's and blue's are a softer on fair skin and super flattering.