window sill and molding

I purchased new construction about a year ago. All interior doors have simple white molding but windows have nothing. Mainly I want to tile all the sills but think that some molding is necessary especially across the bottom to hide tile edge. The house has a modern feel so I want it simple. I am a novice at this but don't want to pay someone to do this.
The sill is 5.5 inches deep. Any suggestions to get me started??
(I don't always trust the advice at the big box home stores)
Thank You