Pretty Lengthy, but this should help.
Your EASHL players skill level is based upon 3 things; Equipment slots, boosts, and player cards. Equipment slots and boosts can be unlocked by accomplishing a variety of things in the games. For instance win a game on allstar as the montreal canadiens alltime team. It's pretty easy. The equipment you unlock will open up a certain number of "slots." These slots can be filled with "boosts." If you have top of the line equipment, each piece will allow 3* slots. Therefore you can use 3 boosts for that piece of equipment. These boosts can be added/changed at anytime as you unlock more boosts and figure out which ones help your player the most. Depending on how many boosts you've unlocked, these can really improve your player.
The other way to improve your player is through xp (experience) points. These are earned through your player's "card." To unlock these cards, you have to play so many games at a certain rating. Your player has an online and offline card. Therefore the xp earned in be a pro will only apply to your player's offline card. Also only the EASHL xp earned will go towards your player's online card. There's no carryover. Check through the pro's "shop" to see how to earn them. The first level is at 20 games @ a C-rating. A C-rating is easy to achieve so you just have to put in the time and play 20 games in EASHL. Then you can add attributes to your player. Once you accept these attribute increases, they cannot be edited. So basically the more you play in EASHL, the more XP you'll get.
The easy equip unlock I have done is to play as Montreal Canadian Allstar team on all-star settings. Gives you 3* Patrick Kane gloves (best level you can get)
That pretty much covers the easy equipment unlocks. For the Boost unlocks, pretty much complete one Be a Pro season and rack up the stats. This will unlock a lot of boosts
http://www.thesportsgameguy.com/?p=2736
This describes the boosts, equipment, and boost packs. Pretty much boost packs will take ur player to a certain level, but will not raise as your player's attributes (xp) increase. The boosts will always add the +1,+3, or +5 (depending on which boost u apply) as your players attributes increase. Basically if you plan on playing online for awhile, don't get the boost packs.
GM For skate, stick, and blade help, check
http://www.eashlforum.com/forum/showthread.php?t=6829
Way to go Padres fans...
This lists all the achievements that can be done to unlock boosts/equipment.