Talk:"Interstellar Tanabata Festival"/@comment-122.58.234.27-20130702072417/@comment-3985255-20130702075225

I would think it would be best to use them in the start so you don't waste exp in the end. I usually did this with my daemons. I'm not sure if it still stays... but according to the Skill Leveling Tips page...

A skill level raises by one level once every 5 levels.

Daemons with same skills
Feeding daemons with same skills will result in a random level up of skill. It is known that leveling up with the same skilled daemons on a maxed leveled daemon will cause the skill level to rise, although at random as well.

Magatamas with same skill
Feeding it will result in a +1 to the current skill level. It does not affect the next skill level up. The magatamas can be used at all levels.

Therefore, it shouldn't really matter.