Purchased eggs with no control over the creation of a "sticky" egg is where most people begin to operate from, so come up with the endless list of reasons why she won't conceive from that point on and start knocking them off the list. 

A random good cow, no matter how proven in the pasture, doesn't mean she'll take eggs. Starting with one proven to do so, be it from experience or purchased as a pregnancy carrier is great way to really start moving the percentage points in your favor. Apply all the same techniques required for successful AI, but dial them all up. Have her in a healthy, but increasing plain of nutrition and body conditioning. Be it dry lot or pasture, control it in such a way that the following 60-80 days are the same as it is leading up to the heat and implantation. This is as hard as it sounds in fescue country when fertilizer rates and rains can have us fluctuating forage quality in what seems like a matter of a week. I'd be looking for elevated levels of vitamin A, do not settle for industry standards, and do not use aged mineral. I don't care what the ads say, I'm not a fan of injection for corrections as they cause a correction which is followed by a transition. We're looking for a steady maintenance with no transitions. I'd be looking to control sulphur levels, especially if the cows are dry lotted or if you know your water source can be an issue. Protien sources are not all the same. I personally would remove any form of urea and even ddgs well before implanting. Alfalfa, clover, and Sorghum Sudan would be preferred over even soybean meal. Be careful with silage. 

Remove every stressor imaginable. Decide what percentage of failure you are willing to accept in order to have a calf at her side. Optimal conditions means she doesn't. Is a forced heat as good as a natural one, no. Does a cow need to be ridden for 5 hours, no? Is it hot, how long does it take for a cow to cool down, how does that affect her even days later? Is it hot enough to consider body temp management additives or fans under shade? Is it cold enough she needs to be deep bedded? Dial up all the "calm cow" mantra from AI another notch. Putting a cow on a trailer is not a good idea, driving 100-200 miles like many do is a terrible idea. If you have to haul them for implant, they need to be trailer queens that load themselves and never shift on the ride. AI techs are not embryo techs, use a proven entity. "The CL feels good" is not the same as looking at it on a screen. Pick and choose where you put your good eggs and have some $50-100 auction eggs on hand for the unclear and undersized ones. Do not turn her back out with cycling cows or bull calves. Follow it with 60 days just like the weeks before she came in heat.

A good recip herd is managed better than a good cow herd. The best recip herds are managed like a race horse farm. It's no coincidence that as success rates increase herd size generally decreases. Unless you know you have very sticky eggs, fully understand the risks of letting it ride, or are working in serious volume, with good eggs being north of a grand there's too much money involved to just be running cows through the chute as if they're being time AI'd. Even with cheap self produced eggs, some of these steps are well worth taking to keep yourself out of the column of disasters. Don't be the guy blaming the guy who sold you eggs because your cows won't take them. He just might have a paper trail that shows his cows like to take the exact same eggs.   

If you do it for long enough you'll start to see a trend. The better you get at it the longer the failures hold on. If all of your failures are cycling/breeding back the next cycle, you're not where you need to be. If you start to notice an increased amount of failures holding on so long that the bull would only have one shot at them, you're getting into the sweet spot.