Seriously, that works! That's how I made my +9 dagger. No, not mirage dagger or shard ro even personal dagger...just daggerEXACTLY.
God, I can't believe people ask for "TIPS" on upgrading.
I hear that if you down a bottle of vodka while masturbating, and hit the "OK' to upgrade button RIGHT as you orgasm, you can make ANY item succeed.
And using this...technique...doesn't always work. Only if you'r character is human female and wearing valkyrie armors/complete mage armor. Then gogo upgrade!