I'm a bit biased because my body is like this, but it is possible to be slightly toned and androgynous. Being thin and having some muscle looks healthier than being a skeleton, plus you won't be a complete weakling. Think a cross between ottermode and twink.
Admin is cute as fuck and his advice is valid, but I just don't agree with the muscle decreasing and the fat increasing (unless you have a complete ripped man body then yeah loosing muscle would definitely help). Also keep in mind that Admin carries his fat in all the right places, but fat distribution varies by person so you might not look as good as Admin if you gain a bit of plumpness.
Last thing, clothing is a big thing to be more androgynous. Wear loose tops (jumpers, cardigans, scoop neck shirts, parkas) and skinny jeans/pants. Go to a fashion thread for more info