Well I think if you want to improve you have come to the right place. Take what feedback you get and experiment to find what works for you. Some of the best advice I got was many years ago from my college mentor, a brilliant watercolorist and art professor, and she said \"Make the darks darker and the Lights lighter.\" I have tried to apply that more and more over these last couple of years back into the hobby. Also one of the best things you can do is invest in some good brushes. Windsor and Newton Series 7\'s, Raphael 8404\'s, Da Vinci Series 35\'s are all excellent brands that I have tried. Once you use a \"real\" brush you won\'t ever touch a GW brush again.
As far as reds go they are hard to do period and it takes lots of practice (and since you are workingon an army you will get plenty). For my reds, i start with either a brown or purple type base (P3 Sanguine base is an excellent purply red) and then lately I have come to use blues and teals to darken it for shading and highlight it with successively brighter reds.
Lots and lots of thin layers is the way to go, but you dont always have tiem when painting an army. (Lord knows my orks are taking forever). As you work you will find shortcuts and \"cheats\" that work for you.
For vampire flesh (I am currently working on a WFB winged vampire, so I can commiserate), I started with a base of VMC French Mirage Blue (slightly more grey than shadow grey) and gradually mix VMC light flesh all the way up to pure light flesh. This has a neat effect of giving it that dead, grey pallor without washing out the \"living dead\" feeling I like, moving from a dark cool to a very pale warm color.
That\'s all I have for now. Invariably I will think of ten other things later. You are off to a fantastic start. Just practice and improvement will come.
OH! One last thing: DO NOT BE AFRAID TO TRY SOMETHING NEW! ITS ONLY PAINT!