Guest posting is my favourite way if I really want to ensure that my link is high quality. I also use backlinking services when I start a site, they don't build as good links as you could on your own, but they build many. You can try this one : www(.)12kbacklinks(.)weebly(.)com Ofcourse there are ones that make you like 100k backlinks, but those usually hurt your ranking in the end, because they spam. Only ever use the ones that seem "real".
I think the best type of link would be one embedded into an article on a highly trafficked website. Can't go wrong with that! Try guest posting on popular blogs!