10X13 ft bathrroom is not small. You could include a freestanding tub in the shower space.

Of course, you may have to have single sink.

Here are the pictures. We are looking to put a big shower. And wondering if we should change the placement of sink? Any ideas are appreciated!

No one can give you useful advice based on these pics. You need to show a floor plan, preferably to scale and with doors and windows shown. But I can say that 10x13 is definitely NOT small for a master bath.

What style are you into(modern, traditional etc)? Any favorite colors?

Post a to scale floor plan if you want help. BTW this is huge bathroom IMO

This made me laugh because a 10'x13' space would fit both of our bathrooms and still have room to spare...so yeah, definitely wouldn't consider this small! But how easy it is to lay out the fixtures you want will depend on where the doors and windows are (and whether or not they can be moved), so you'll get the best advice posting a floor plan.

My master is approximately 12'3" x 11'5" I have a double vanity, 66" tub and large enough shower 44" x 60" as well as having our toilet in a toilet room. Your bathroom is not small by most standards.

You want help, then you need to post a 2D floor plan with all measurements.