The name of the pack is tongue in cheek. What really makes an expert pack, anyway? This pack has custom recipes, but is not progression based. Most recipe changes are made to make it a more cohesive pack. You can start with any mod, but at some point will have to go through all the mods to complete the pack and craft creative items.
No World Gen
This pack has no natural ore gen, except in the Beneath. You will have to go through Ex Nihilio and sieve for resources. Eventually you'll be able to make Mystical Agriculture seeds and the void ore miner from Environmental Tech (as well as mine in the Beneath). Also, you can gather resources using the methods from Botania, Astral Sorcery, and Immersive Engineering.
The main mods in this pack are Ender IO, Immersive Engineering, Botania, and Astral Sorcery. Like stated above, start with any one of those mods, but you'll have to go deep in all of them in order to complete the pack. Other tech/magic mods include Calculator, Cyclic, Reliquary, RFTools, and some Thermal mods with certain machines disabled to remove redundancy. Refined Storage is the main inventory mod. Extended Crafting is used for late game and creative items. Full mod list below.
A few mods for exploration include, Recurrent Complex, Hunting Dimension, Simple Void World, RFTools Dimensions, and Roguelike Dungeons with custom loot. Pam's Harvestcraft is also included along with Cooking for Blockheads, Spice of Life: Carrot Edition, and Nutrition to overhaul the food system.
Quests are included using Better Questing. This isn't a tutorial modpack, you should be somewhat familiar with modded Minecraft and JEI. It's really just, "craft this item, get this reward." No random loot chests; most rewards you can chose from a list on which item you want. Use it as goals to achieve while playing the pack, something to work towards.
Several mods are included to help with base building, including Chisel and Unlimited Chisel Works. Also included are, ArchitectureCraft, BiblioCraft, Blockcraftery, Environmental Materials, Flat Collored Blocks, MalisisDoors, Quark, xNicex, and Xtones. Chisel and Bits, Extra Bit Manipulation, and LittleTiles are also included. Quit worrying about progressing and build a pretty base.
Minimum 4 gb of ram required, 6 gb recommended.
Full Mod List: