I have a very difficult time concentrating during Salah. I always think about other things and even forget that I am praying. What do you recommend for me to increase my concentration and focus on Allah SWT during salah?

Salat is the cream of all our actions and worship.
Its good that you are concerned about it and want to make it better.
Ulama (schoalars) suggest a list of things to help making ones concentration better in their salat.
I will list a few and you can research on the rest.
1. Perform your wuzu with concentration. There is a short dua to be recited before every part of wuzu that one performs. This should help a great deal whislt we do wuzu.

2. Perform the recommended acts before salat eg. Reciting azan and iqama ( the call of prayer), brush your teeth, put perfume, give a small sadaqa ,wearing clean clothes, combing your hair etc.

3. In your daily activities try making an intention that you are doing everything even wordly for the sake of Allah and this way your prayers too will be rich with concentration.

4. Read a few books on line eg philosophy of prayer, meaning and commentary of salat by Agha Mohsin Qaraati. His books are simple yet profound.

5. Try to inculcate in yourself that whatever action you make in salat is the most important one, therefore all the actions will be done with concentration inshAllah.

Follow these rules with Tawakkul (trust in Allah) and tawassul (asking help through the Ahlbayt a.s). After all, in every worship we also need the help of Almighty Allah through His chosen servants.