QI work closely with one teammate, and we get along great except for one thing. I like to plan things in advance, and she is one of those last-minute types (but she always comes through in the end). How can I get her to work a plan instead?
AIt's fruitless to try to change someone else; focus on successfully collaborating with her and benefiting from both styles.
The inner game
Relax, take some deep breaths and ease any judgment about her approach to work. Let go of annoyance and frustration, and prepare to seek solutions.
Start by listing all your colleague's strengths. Focus on ways in which she is different from you, and the benefits this brings. If you're drawing a blank, look at her perceived weaknesses from the opposite perspective, turning "flighty" to "flexible."
Then look at yourself with her eyes. Rigid? Stuck in your ways? What you consider to be organized and on-track may seem very different to her -- and just as frustrating as her style is to you.
To help understand this more deeply, study up on Myers-Briggs personality types. The differences you're describing are aligned with the Judging-Perceiving dichotomy, which relates to how you deal with your external environment. For example:
•Judging types like plans, like to be done before the deadline and get stressed if things are not buttoned down.