I've been trying to grow my sideburns but they are a bit wispy, is there anything I do to thicken them up a bit?
Unfortunately there is nothing you can do except shave them off. It is better to have no sideburns then little tufts of bum fluff on the side of your face. Facial hair is a difficult one, you can either do it or you can't. Some men's faces grow better in different areas, but take some consolation of the fact that a lack of sideburns will leave you looking younger.