To develop that winning herd, you must keep in mind that culling should be at the top of the list. It is too easy to keep everything.
Try to match the good points of one rabbit to the faults of another when breeding. Some lines carry that massive head, or crowns, while others carry top line, body size or good bone. The biggest part of breeding is trying to piece all of the good parts together. It is like a jig saw puzzle. And just when you think that you have it figured out, the pieces don't fit anymore. Some lines cross well with each other and others don't. It will take some of trial and error and good record keeping to figure out the puzzle. I personally have had to scrap one entire line when we first got started because it just didn't click.
Try to get Hollands that are compatible. You can line breed and inbreed to intensify or fix traits. Keep in mind that you will fix the good along with the bad. Outcrossing is when you breed two completely unrelated animals. Outcrossing will always help with vigor. Keep in mind that the key word is cull. It is something that we must all do in order to get that great Holland that we strive for. Cull strict and cull hard for what the Holland Lop Standard calls for.
One thing that works for us is breeding father to daughter and then taking the father back to the granddaughter. On occasion we breed an out cross, but not very often. We like to work within our lines. This has really improved our rabbits. Keep in mind that everyone has their own way of producing that winning Holland.
Another important tactic to develop a winning herd for beginners is to purchase the best buck that you can afford. Remember that good Hollands are hard to come by, so be prepared to wait, but try to get the best buck that you can.
Lastly, remember to cull, cull and cull again. Good luck!