Start small with something you really would like? Let’s take the example of planning a vacation, (even thought this might be big, we can all understand this vacation vibration) Remember the excitement you have planning your vacation because you know it’s going to happen. This high vibration encourages you to eat better, exercise, buy new clothes to get in shape for your holiday, and you’re happy and inspired to take action. You look for new clothes to wear on your vacation and maybe get a new hairstyle. I hope you can feel your vibration rising here, and this ‘feeling’ is where you want to be to get what you want! The added benefit is that you feel good! Reinforce with your intention, know it will happen, and then allow it to unfold. The ‘Law of Allowing’ is allowing our desires to unfold, and is much like trusting, and not checking every day to see why it hasn’t manifested yet?
Be observant of what does show up in your life that may be similar to what you want? If you are not crystal clear on what you want, the Universe may give you something that is similar, though not an exact match, (in the case of a vacation, you are crystal clear on where you want to visit,  how you will get there, and the experiences you would like enjoy when you arrive at your destination)?

The Law of Allowing is accepting things as they are, right here, right now. Start by being grateful for where you are, and allow the people in your life to be as they are, even if they are doing something that is different from your viewpoint or annoying you in some manner.
If you are not getting excited about what you desire, you may want it for the wrong reasons, and your vibration will not get high enough to allow it to manifest. Some action is required to get you what you want. If you want to reduce by 10 lbs to look and feel good on your vacation, you will need to change some habits and do some exercise. And you are willing to do this because you are in a vibration to do so, and you will see results and we usually do get results.
Everything is possible, and when we go in a new direction we get excited about our life again, and it gives us renewed energy and fresh ideas that make our lives better.