In one sentence, describe what the following article is about:

For example, if they love to go shopping, you could incorporate shopping into the birthday plans by starting out the day at the mall. If they hate crowds, you could choose activities where you'll be more secluded. Keeping their interests in mind will help you choose activities you know they'll enjoy. Don't feel obligated to spend a lot of money for your significant other's birthday if you can't afford it. Look for cheap or free activities you can do together; your significant other will still appreciate the effort. For example, you could take your significant other to a free outdoor concert at the park if they like live music, or find a museum that's having a discounted or free admission day. If you're planning on doing something outside and the weather is calling for rain, look for a new activity you can do that's indoors. If it's going to be a nice day out and you hadn't planned anything for outside, consider squeezing an extra activity that's outside into the schedule.

Summary:
Choose birthday activities based on your significant other's interests. Choose activities that are within your budget. Check the weather forecast before you finalize your plans.