Are you using a quality brush, not one out of the 99p bin?
IMO, painting tile looks horrible, and I'd always retile.
But that's me.

My brother painted some tiles white with what claimed to be
special tile paint but looked just like over-priced gloss
paint. A year later it was all yellow, and he had the tiles
all taken down.


I agree. It's the same with gloss over radiators - ends up horrible. The
only time I painted over tiles was on a 1940's fireplace that I couldn't
afford to replace. The tiles were mostly mushroom with some yellow I didn't
like. I decided they would look better off-white. Because it was an area
with heat I decided to use spray radiator paint, hoping it would discolour
less. It looks great - 10 years on! Still haven't replaced it - got a bit
fond of it.

The tips for best use: mask the grouting; under spray rather than over coat
for more realistic finish; don't go right out to the edge (as with applying
nail varnish), it looks neater - although a prob if you are doing white over
black or other big change; don't spray directly, spray onto something else
and lightly sponge on, building up just the right amount of cover. Any
spillage into the grout draws the eye, points out it is paint, and spoils
the entire effect, so be very very careful not to go over the edge of the
tile.

Having said all that, I would agree with Ian, retiling would be the nicer
option. I wouldn't think of painting/ masking all the tiles you have in a
bathroom! We have tiled only twice in our lives and it turned out ok - but
it is time consuming and expect to curse a good bit. It was a kitchen area
and we had a lot of cutting to do for sockets, so if your bathroom area is a
plain wall, go for it! White tiles are plain ,simple, cheap and look very
fresh.

My unexpert tips for tiling:
Two people make for less chance of fouling up, 1 to scrape the grout on and
the other to stick, and 2 sets of eyes for numpty-mistake-avoidance;
Clean the area to remove loose stuff before starting;
Use a 'comb' to put the tile adhesive on with ridges - best results for
sticking and evenness;
Don't put on too much tile adhesive, it dries quick and you will be going
slowly as a newbie. No more than two tiles ahead.
Use plastic spacers or matches to leave spaces between tiles for grouting
later. This will be more professional looking than if you just guess the
spaces. Plastic spacers can be pulled out and reused further along - don't
buy enough for every joint in the room!
Use darker grout than the tiles, never use brilliant white grout with white
or pastel tiles (OK with strong blue). Why? Because it looks like Tippex
on a tooth, and the least discolouration stands out like a sore thumb! The
tiles won't discolour, the grout will. Light grey or biege with white tiles
allows the tiles to be the star, not the grout. This grout will just look
off-white when finished, rather than coloured.
The bigger the tile, the less tiling (and grouting) you will have to do.
Mosaic tiles look great but are a b*tch to grout. You could put a little
border of them in if you were feeling brave

Final tip: the cheaper the tiles, the more likely they are to snap in half,
but for a newbie it means you don't have to worry about cost every time you
foul up. Buy 10% more than you need at least.

Good luck
Suzanne