The style of wedding dresses will probably depend on four factors as follows: your personality, your budget, your culture and your future husband. There may be more factors but these four are the most common ones.
Firstly, it depends on the type of your wedding. Are you going to be married in a church and will the reception is inside a hall, or are you going to be married in the garden, beach, or in some enchanted island where guests will be free to roam around and then gather in an outdoor tent to offer their best wishes and congratulations?
An outdoor wedding would narrow your choices. You will certainly want to consider not wearing a bridal gown that would require you to wear high heels, unless you want to leave permanent marks on that beautifully manicured lawn. Wear a bridal gown that looks right with a pair of sensible but stylish flats to keep you from boring holes on the ground. For practical reasons, you may want to seriously not wear a long, down to the ankles type of dress. This will spare you from having to deal with a muddy hem. Make sure the hem is heavy enough not to fly up at the first sign of a sudden gust of wind.
For the same reasons, a train is not ideal for an outdoor wedding. You will likely find it covered in mud and grass stains by the end of the reception. If your wedding dress comes with a veil, keep it weighted to keep it from blowing around too much, unless again you'd want your groom and pastor to chew on the lace by the end of the service, or risk the veil pin landing on someone's cake.
Your personality tells me what you wear to your wedding and I'll tell you what kind of person you are. It may ring true, but remember that you need not be forced into wearing anything because its tradition or your rich mother-in-law has done the cherry picking in some designer's rack. Your wedding dress is you, inside and outside. Let it bring out the message on this special day.
Also, you'll have to take your body type into account. If you have a good figure, show it off within the limits of decency, of course, especially if you're getting married in church. Not that the pastor's opinion should carry weight in the choice of your dress, but it is his church nevertheless, so be respectful of the place where your marriage will be solemnized.
A sleeve wedding dress (one that clings to your body from neck to ankle) looks best on someone with a slim figure and curves to show off. If you've always been proud of your hips, look for wedding dresses that flair out a bit at the waist. If you want an overall slimming effect, do not invest in fluffed up sleeves and huge skirts, or you will look bigger than you really are. A skirt with lots of fabric so that it drapes and folds would be ideal. Do not add puff to the lower portion by adding a hoop or other fabric.