For starters (apologies if this step isn't necessary for you), I like to make a timeline where the past is behind my dominant shoulder, the present is pointing down to the floor where I'm sitting or standing, and the future is to the front of my dominant shoulder. In other words, I use my dominant hand to point to the place in time. The future is forward, and that connects to the stress falling on the future ending, for example, "yo iré": the last syllable gets the stress, and that means that we are thinking ahead (into the future). I hope you see what I mean.
Now, you asked for memory tricks to remember the specific endings. Usually the mnemonics that work the best are very personal. For example, I learned "sonrisa" by thinking about looking at a nice sunrise and smiling. However, I will make a stab at getting you started.
é: yo iré: the last syllable sounds a bit like "ray" -- ray of sunshine. I am pleased to tell you that I will go to your party. This pleasure is like a ray of sunshine. "Sí, iré a tu fiesta."
ás: tu irás: the last syllable sounds a bit like Raas, a thrilling traditional folk dance form of Gujarat & Rajasthan India. I can ask you if will attend the upcoming Raas performance: ¿Irás? ¿Irás a Raas mañana?
á: él/ella/usted irá (I would pick one as the paradigm, for example, "él irá": just take the S off the end of the previous one. (This follows a general pattern.)
emos: nosotros iremos: start with "yo iré" and put "mos" on the end. If you have trouble remembering this, you could think, "Most of us will be going."
éis: vosotros iréis: hmm. I learned Spanish in Mexico and don't use this form. Perhaps you could also connect it to "iré."
án: ustedes/ellos/ellas irán: Here I would start with the singular "el irá" and add an N, because in general one goes from singular to plural by adding an N.
As you can see, I believe it is easier to learn endings if you learn them as part of an actual verb conjugation. In other words, I recommend seeing the chart in your head (and pronouncing the chart) as
However, as one "sees" or "hears" this, one should also keep in mind where the stem ends and where the ending begins.
A fun way to practice future would be to take sentences from your book that appear in the conditional and just switch them over to the future.