Boost SEO with High DR Guest Posting

I am looking to substantially improve my search engine rankings through an effective guest posting project. Here's what my project entails: It's pivotal to aim on websites with a Domain Authority (DA) range of 40-80. The focus is to improve rank on some words and increase traffic. The site is a SWEDISH cleaning business site with local customers. PS! I WILL NOT ANSWER AUTOMATIC BIDINGS WITHOUT READING THE POST.