I get a lot of critical feedback from my boss and I don't always know what to do with it or how to improve. Sometimes I don't even agree with the feedback. What should I do when I don't think the feedback is correct?

This is a difficult question to answer, I would love more context in order to respond thoughtfully, but I will share this- a work enironment that is build around psychological safety, one that encourages healthy debate and conflict is (IMO), the envinroment that breeds the most creative and successful teams. It's good to disagree and work together to come to an agreement, or comprimise, but your leader may have context you don't have, and they may not even be able to share that context. In some cases, you may need to agree to disagree. Feedback is a gift, but how you take and apply that feedback is what will help you grow, mature in your career. Some of the hardest feedback I have received has been the most crucial to my development and success.   

That’s a tough position to be in. Hopefully you have the type of communication in place where you feel safe to discuss it. If you do, I recommend approaching it from an objective perspective. There could be nuggets of growth opportunities within the feedback you receive.

“... Don’t always know what to do with it…”

Does this mean the way the feedback is given doesn’t feel productive? Or is something unclear as it relates to next steps?

“... I don’t even agree with the feedback…”

It’s completely fair to disagree with the feedback you receive. I would challenge yourself and ask why do you disagree? Could this be a growth opportunity or is the feedback completely off-base?

Giving and receiving feedback is a skill. It’s a muscle that needs to be developed. This doesn’t mean that you need to take action on all of the feedback you receive. It’s outside of your control on how feedback is given to you, but it is in your control on how you respond.

I think you need to acknowledge this problem with your boss, especially if you have data to back up why their feedback isn't helpful or is steering the strategy/project in the wrong way. Being able to solicit critique and then facilitate meaningful discussion about the work is key to success on complex marketing teams. Make the discussion about the work and about the impact it will or will not have on your customers, and not about the person.

If this continues and the critical feedback keeps coming in and is unhelpful, I would simply just start to ignore it and continue to move on by making the best decisions you can for the project and company. And then maybe try to find a new leader to work for who understands how to give proper and helpful feedback. Surrounding yourself with people who want to help you learn and who challenge you by giving you autonomy and empower you to drive next steps is going to do wonders for your career growth and growth as a person.

You don't have to agree with feedback. But you do have to be open to hearing it, especially from a boss who has power over your career and performance reviews. And - I hate to say it - but not all bosses will have your best interests at heart, so not all feedback might be valuable.

The best thing you can do is to take a step back and think about the feedback and where it might be coming from. Ask for specific examples and how they would have preferred you handle the situation or the work. And try to think about where they might be coming from - is their boss on their case about something, and that is trickling down to you? Is there an urgent deadline coming up that they're worried about missing? etc.

Choose one thing that you do agree with to actively try and make a change on. Work at that, and give your boss clear updates on how you have been working on that item so they can't miss it. Once you feel confident that that item is no longer an issue with your boss, move to the next item. You do have to make a change since the feedback is from your boss - but take the time to understand it so the change also benefits you and your career.