Safest way is to buy legit links with high TF/DA and then link back to your site - then you'll need to spend a good load of money to achieve that.
Blackhat way to increase DA - just a whole lot of automated built-backlinks will gradually increase DA to 40+-ish
There is no blackhat way to increase TF - a site that is trusted and with a clean link profile, will have TF, and only through these sites linking back to you will increase your TF.
Unless, if you purchase sites with high TF, and do a 301 back to your site - that will work as well. But prepare to spend $$$ purchasing sites with high TF, as these are expensive as well.