I would suggest you start adding photos to your bathroom ideabook. Add lots and lots of pics, be instinctive about it. If you like a bathroom, add it to your book. Then after a while, look through your ideabook and you'll see a style emerge. Similarities in tiles, style of vanity units, colours...
Draw a floor plan to scale and a toilet, shower, bath, vanity to scale on separate paper. cut them out and shuffle them around on the bathroom floor plan. There are apps or computer programs available that you can use for that too. Here's a free one that's quite easy to use: http://thebrick.icovia.com/

Look around in bathroom stores, DIY stores. See what you like.

Maybe you can remove a wall, change a doorway...

I agree with Caroline. In the meantime, I would work on taking off the border. How much of a renovation are you looking at? Also, what type of look do you like? Ie. Elegant, spa, antique? Figure out a "feel" you want and the type of reno and it will be easier to help.

Thank you both.