Pack it tight, but don't use a lot of small pieces. Then temps will be stubbornly low, just like Kbb or other cheap briquettes later in a cook when the ash becomes an issue. That's one thing you're trying to get away from, right? Mix the sizes of the pieces as symmetrically around the ring as you can without being too anal about it. One thing you can do is to use mostly medium and large pieces, then dump small pieces in to fill in the holes. I did that yesterday with a bag of crappy lump. Lump's like that. Sometimes you'll get a bad bag. As someone recently said, look for "fluffy" not flat bags.
Another thing I'd suggest trying is to put a layer of briquettes on the bottom. The briquettes will burn clean on the bottom, and it adds longevity to the cook. I also often light the lump with half a chimney of briquettes, as well...especially for long cooks.
There's a few issues with lump, but if your tastes are like mine, you'll enjoy tasting more of the smoke flavor from your wood. Not all the time, though. Recently I used some Cowboy lump, used NO wood at all, and ended up with some of the best smoked chicken I've ever had. You'll have a good idea if it's gonna smoke by just looking at the level of carbonization of the lump when loading the ring. Royal Oak is usually highly carbonized, though. Hope that helps.
