I agree that having a picture would help with giving advice about looks. Of course, only if you feel comfortable posting it.
But in any case, there is probably lkttle you can do about the sound of your voice without hormones.
I think you should try working on your looks. For example, it is true that old ladies often have short hair, but there are for sure very masculine hairstyles that you will not see on grandmas. Very short sides and back but significantly longer top (spyked or not) may be one of them. If you search google you will find lots of them.
And for clothes, being 30 you probably won't love it, but you could try with typical younger boys clothes? Like baseball caps, or tshirts with stamps? I guess it is not ideal... the fact is that many older women tend to dress (obviously) less girly and more androginous.
The body shape can be modified a bit wearing full lenght binders and shaping boxers (I don't know if you call it like that in english, but underworks sells them, they are boxers in a material similar to the one of binders and help with the shape of hips, I think many shops have them).
Body shape is one of the main factors when gendering someone. You can find helpful tips (at least they were helpful for me) here:
http://ftmguide.rassaku.netYou probably have already seen it, and it is not specifically intended for not being mistaken for an old lady, but it has good advice for anybody.