bptubbs is absolutely correct. Especially for what you are looking to get out of it. Eat it.
People get so caught up on that BA% number, but changes in BA don't occur in a vacuum. ROAs with the highest BA are often the most compulsive, addictive, recreational, and dangerous. It would be most "efficient" to IV your meth, and smoking is right up there with it. But, for one, you will compulsively re-dose in order to chase thar rush, and two the high they provide is not very conducive to doing anything productive that doesn't involve your dick.
Eating it is going to provide the longest lasting high, with the least comedown. It may technically result in lower plasma levels per dose unit, but its affect on future dosing and tolerance more than outweighs any loss in BA.
I see you corrected yourself and say you do actually want a bit of a rush. I wouldn't say insuffalation results in a rush, per se, but the change from sobre to high is more noticeable and quick with this ROA, so you could snort your first dose. If you really want a rush without smoking or IVing it then you could plug it. Just remember that subsequent doses will have much less immediate effect, so after your first dose of the day don't go chasing a rush, if its been sufficiently long between doses that you could dose with a rush in mind, then it is much better to just pack it in for the night, lest you suffer a far worse comedown.
You are clearly very new to meth, and I know right now it feels fucking magical. But if you aren't very careful with how you abuse it, how you dose it, how long you binge it, etc. etc. This honeymoon period can wear off very quickly. If you want to get as much out of the drug as you can you need to avoid multi-day binges and re-dosing before the high has worn off.