Hello babaladeexx
I've just taken the existing tiles off from round the bath, and used tongue and groove cladding to dado rail height all round the bathroom.
(I tried to see how it would look with cladding upto picture rail and ceiling height, but I've got very high ceilings and I don't think it looked right.)
I didn't tile primarily because of the cost, but also because I thought cladding would be easier and the fact that my walls aren't flat.
I bought the dado rail with a slot so that the cladding fits behind it, this made fixing it a lot easier as it doesn't have to be pinned onto batons. I also replaced the skirting and ran the bottom of the cladding behind that. I think you can buy skirting with a groove, it fits flush to the wall and the cladding slots into this, but this was a lot more expensive when I priced it up. (I bought my bits from a seconds wood yard)
It was straightforward, and I don't have a lot of experience with carpentry. I borrowed an electric mitre saw and this made cutting the lenghts of cladding to size really quick.
One tip is that its important to get the first piece of cladding vertical, dont rely on placing it against the wall and this being perfectly plumb. I attached my first piece on each wall with screws and wallplugs so that when I fitted the following pieces against it it didn't move out of the vertical. Especially with a long run, a few degrees off vertical on the first piece will be exaggerated and noticeable by the end of the wall. I then filled the holes and painted over.
If your wall, where the first piece is to be fitted against, is really not straight then its best to fit the first piece just under a piece of cladding's width from the wall, (as in wallpapering) Then the end piece can be planed/cut to fit perfectly and coaxed into place.
From what I've heard tiling becomes more fiddly if your walls aren't flat and your corners not square. Also its easier to cut wood to fit than tiles.
I followed some advice from this board, (thank you to whoever posted it) about boxing in pipes at skirting board level, and this worked brilliantly. You fix a baton to the wall at the height of your skirting, it needs to be slightly thicker than the distance the pipes protrude and 2-3" wide to provide sufficient support for the skirting. Then fix the skirting to the baton. I can try to explain this better if necessary! You end up with a mini shelf at the top of the skirting!
I can't comment very well on boxing in under the sink if you need to go higher than skirting level. I've seen some sinks with a curtain round that looks ok . Its stuck with self adhesive velcro to the base of the sink. This is an easy option. Otherwise I guess you could fix a 'shelf type of thing' just higher than the pipes and box the front of this in attached to a baton on the floor.
I hope this helps and I hope I haven't made it sound unecessarily complicated!
Amanda