All the way back to 3rd edition I've used a brilliant program called Army Builder. It makes army list creating more about the army list and less about calculating points cost. It supports Warhammer Fantasy Battles, Warhammer 40k, Battlefleet Gothic, Blood Bowl, Warmachine and pretty much any other miniature wargame I can think of.
|Every unit, wargear option, psychic power. It's all here, folks!|
Please note that I have no commercial interest in this product and receive nothing from the authors for writing this blog post. I just use and like it a lot, and that's why I recommend it.
If you don't want to spend money on making your list building easier, there is a free solution! At least if you have Microsoft Excel and play Necrons or Eldar. YouTube user matteo311GameMovies have made army builders for Necrons and Eldar. He's giving these away for free, and explains about them in this YouTube video. If you support him by downloading the army builders, commenting on and spreading his videos, he might just make the next one for your army.