As a 1st level spell caster I enjoy taking the Metamagic Feat: Rime Spell, which entangles the subject damaged by your cold spells for 1 round / level of the spell caster. Then you take the Metamagic Master Trait and have it apply to the a First level spell. I enjoy using Icicle Dagger. This trait allows you to -1 from a certain spell's metamagic level usage.
So at first level I have a spell that on a melee touch attack deals 1d4 points and entangles the target if you even deal 1 damage to them.
I was curious about whether the conjuration considered the dagger to actually be a real dagger, or a spell. Upon looking up the conjuration school in the Players Handbook it says that if it has a duration it's still considered a spell and is held there solely by magic. Therefore the Rime Spell would still actively affect it each round? Below are the terms to make up your own mind. DM discretion I suppose
Icicle Dagger
School conjuration (creation) [cold]; Level sorcerer/wizard 1, summoner 1, witch 1
Casting Time 1 standard action
Components V, S
Range 0 ft.
Effect one icicle
Duration 1 minute/level
Saving Throw none; Spell Resistance no
You create a masterwork dagger out of ice. The dagger deals 1 point of cold damage in addition to normal dagger damage. If the dagger leaves your hand for more than 1 round, it melts and the spell ends. At 6th level, the dagger functions as a +1 frost dagger. At 11th level, it gains the returning property when thrown, melting away and reforming in your hand just before your next turn.
Rime Spell (Metamagic)
Benefit: The frost of your cold spell clings to the target, impeding it for a short time. A rime spell causes creatures that takes cold damage from the spell to become entangled for a number of rounds equal to the original level of the spell.
This feat only affects spells with the cold descriptor.
Level Increase: +1 (a rime spell uses up a spell slot one level higher than the spell's actual level.)
Conjuration Creation: A creation spell manipulates matter to create an object or creature in the place the spellcaster designates. If the spell has a duration other than instantaneous, magic holds the creation together, and when the spell ends, the conjured creature or object vanishes without a trace. If the spell has an instantaneous duration, the created object or creature is merely assembled through magic. It lasts indefinitely and does not depend on magic for its existence.