My idea for spellements would be to have "extra credit assignments" from our ravenwood teacher (arcanum teacher for those in polaris+) every 5 levels. These quests would be pretty straightforward by casting a certain spell X times (like cast rebirth 25 times), or it could go into farming (defeat Malistaire the Undying 3 times). After these quests are completed, you can turn them in for spellements depending on difficulty (longer quests = more spellements)
Also I have ideas for new types of spellements: -Minion Summons (upgrades will either give minion stats like +hp, dmg, resist and -boost, or give your minion access to new spells, like a rank 2 golem minion can cast all rank 2 spells instead of only 1 pip spells)
-bubbles (upgrades will either increase the +dmg or give a -dmg to the opposite school, for example a rank 2 wyldfire either gives +30% fire damage or +25% fire damage and -5% ice damage