Now here's an example of how analysing Mark Bridger, his character, lifestyle, beliefs, hobbies, etc can help creating ideas where April might be.
The following is all just my opinion, people might have a completely different view of him.
From what I read about him here and in articles and from his photos I don't think he's a psychopath. I think he has genuine feelings for other people and does not set out to hurt anyone. I think he is made up of a soft side with deep, loyal and passionate feelings towards others, and a more wild, untamed side, which is prone to sudden outbursts of anger. He is sometimes ashamed of his soft side and thinks he isn't "man enough", he's insecure under his manly exterior. This leads him to seek constant approval from others. I don't think he's evil but he can become violent if he doesn't control his temper. He's an outdoor person who can easily do hard physical work. He is more guided by physical and emotional needs than by logic, planning and reasoning.
Whatever he did to April, it "happened". Either it was a stupid accident, something went terribly wrong, or he did something to her out of uncontrollable anger, even hate. He didn't plan for it, he snapped, and he regretted it almost instantly. He was (and still is) filled with remorse and guilt. He was not able to just dump her in the trash or down a mineshaft, or dismember her or such things. He took her body to bury her somewhere in an attempt to give her at least that much respect and care. I think he chose a "nice" spot, he knows the area well, so he would have chosen a spot he himself liked. He buried her, arranged her properly, maybe even wrapped her in a blanket or something. He might have marked the spot somehow.
Of course, the need to cover up his crime to protect himself is stronger than facing up to the truth and come clean. He's too insecure to do that, he fears the response he will get from family and others.
These are my thoughts. I think LE should look in areas where digging is possible, and ask his friends and family if he had any favourite spots in the area, and search there.