The most important thing to know when designing spells is:
(Note that this can be increased through the use of 8-pt Magic Skill Levels).
If you start a new character with a Magic Skill, you must either:
You are either a full-time wizard or a dilettante, and a wizard simply doesn't have time to learn about non-essentials like fighting or body-building. If you start at dilettante level, your lack of application will be reflected in the size of any magic pool and skill-level, since 30 (20% of 150) points doesn't go that far.