While women admirers may wish they had your bust to take to the beach, if they knew the headaches your ample bosom caused when buying swimwear they certainly wouldn't want to have to take your breasts bikini shopping. Regardless of your body shape, the most valuable advice for all women before they go shopping for swimwear is to take inventory of your best assets.
Since it is already established that your boobs are big, you need to decide whether you want to make your chest feature as one of these assets on not.
If you consider your legs, bum, hips and or waist are your best assets then you can promote your lower half without necessarily downplaying your chest, however if you prefer the way your upper body looks then you will want to choose a swimsuit that emphasises your breasts.
If you decide you want to make your breasts a prominent feature then a sliding triangle or a bra style bikini is best.
If you go for a sliding triangle, then the firmer your breasts, the less coverage you can afford, but for adequate support to feel confident frolicking in the surf then you really want sufficient material in the triangles to cover all of the breast tissue. The great thing about sliding triangles is they provide easy adjustment, so you can slide the triangles into position to ensure they hold you in just right. This is a real bonus for broader chested women. However as easy as they are to adjust, they will just as easily readjust on their own. One tip is to slide the triangles into place so they suit your body and then put a few stitches in to secure the cups to the string so it can't slide.
Bra style bikini tops usually come in either the sports style bra with a thick band under the crease of your breasts or the underwire style. The sports bra bikini top is great for movement and swimming with confidence but it usually comes at the cost of fashion and style. Underwire styles are usually padded and provide good support and lift your breasts up for great cleavage, but they tend to cost more and will not last as long. They typically fasten with a clasps at the back which do not provide much adjustment and the clasps also tend to break well before the bikini is worn out, no matter how much you pay. And they are always guaranteed to break at the most inconvenient times.
A halter is a must for bustier women. For comfort you will want to ensure the straps are nice wide bands, the thicker the better, and not too stretchy. A string tie behind the neck is not going to provide adequate support, and strings tend to be too stretchy so you will need to tie it tight, and then it will likely cut into the back of your neck and begin to hurt.
If you want to downplay your breasts then a bandeau can effectively achieve this. Bandeau bikini tops are tricky if not chosen correctly. It is important to ensure the band is wide, and preferably padded with moulded cups. If it is too narrow then you will either be spilling out over the top or otherwise always pulling it up and worried you will fall out the bottom. You will also want to ensure the band continues wide all the way around so it contains your breasts to the sides, and bandeaus that tie at the back offer the best adjustment.
Adding a halter to a bandeau is a great way to add support to your bandeau top. If the bikini doesn't come with one you can add your own by looping a Lycra band (available from gym and activewear stores) around the middle of the bandeau and back through itself, then over your head.
Once you have got the top sorted chances are unless separates are offered you won't have too many options with the bottoms.
If you have a smaller waist then tie sides will balance your larger bust nicely and be very flattering.
If you have a larger bottom and hips and are conscious of them then you don't want anything that will draw attention to them. You will be using your ample bossom to draw attention upstairs. Darker solid colours and no stand-out features like embellishments, frills etc are ideal for the bottoms. If you are going for a print then smaller prints should be used on your less favoured assets.
If you can find a bikini with large prints or bright colours up top and a darker solid or fine print bikini bottoms then this will best compliment your body.
And always remember, a Brazilian cut bikini bottom that cuts across the buttock cheeks is always more flattering than using a lot of material to try and hide the things you don't want people to notice.