I mix both as well, but I keep the split close to seven niche links out of every ten, with the other three coming from general sites that have real readers. The part I check first is not the domain, it is the exact page my link will sit on. I open that page and look at whether it ranks for anything at all in search, and I count how many outbound links are already on it. I learned this the hard way last year when I placed a link on a general site with strong traffic, but my link went on a page that had more than eighty outbound links and linked out to casinos, loans and essay sites all at once. That link did nothing for me in two months. The same month I placed a link on a small niche blog that only gets about four hundred visits a month, but my link was one of only three outbound links on a page that already ranked for its own topic, and my target page moved from page three to page two in about three weeks. So now I check three things before I say yes. I check that the site has steady traffic over the last three months and not one sudden spike, I read the last five posts to see if they read like real articles or filler, and I check that the exact page has fewer than ten outbound links and none of them look like spam. If the general site passes those three checks I take the link, and for anchors I keep most of them branded or plain, with only one exact match anchor in every ten links, because that is what kept my profile looking natural when I checked it later.