You should start on the base. Working in your flaws, as your ego. In fact, this is where everyone should start if someone is trying to do something by itself. It will affect directly your magick by improving the way that people see you, but the best part of it is that your magick becomes more likely to bring results since you become less desperate about the outcome.
After that, at least while you do that, you should start working on your friendship with the girl. When we’re talking about long-term relationships, the friendliness between the couples is one of the “glues” that holds things together. You can flirt, kiss or have sex with anyone that wants two, but there’s no lasting relationships if there isn’t a really good friendship between the couples.
After that, work on bringing nostalgic memories from your past together as you work on reaproximation itself.
Then, work on bringing regrowing love, and let it happen, little by little, as the contact flows naturaly, don’t force anything. Then, when you both are already close, work on the lust, the sexual attraction.
In the end, after it all, work on evolving the relationship. Not on biding, development.
This approach works pretty better than obsession itself. Obsession normally ruins relationships instead of making them lasting. But in your case there’s love. There’s only a month after the breaking, and love is a feeling that is pretty difficult the get rid of.
So you should seek this plan strictly. And the most valuable tip here: be patient and know that your outcome is inevitable.
Pm me if you have any doubt. Good luck.