It really does depend on the grammar function itself and also the age/ability level of the students.
Most students hate learning grammar, the best way I've found around it is by teaching it to them without them knowing what they're doing. For instance, when teaching propositions with young learners, I have them make a drawing of some treasure and hide it in the room, then they have to guide me to where they've hidden it using the target language 'It's under the desk' 'It's behind the chair' and so on. Once they have that down I usually have them follow up the activity by writing the rule down in their notebooks.
For older learners, I do things like set up situations and give each student a specific role within a discussion, a personality trait or a task. The learners then incorporate the target structure in to their 'character' and I let the role-playing begin. If it's a more complex structure, I usually make a handout prior to class that outlines the rule and gives examples that I give to the students. After they've read it and created their own example sentences, I move them in to a game or activity that uses the structure so they are practicing it in a more fun and digestible way.
But again, if you give us an idea of what grammar structure you're trying to spice up, I'm sure we could be of more help!