EDIT: sorry, I read your comment in your original question
The main thing is to learn how to recognise the three main groupings of verbs - godan, ichidan and irregulars. All the ichidan verbs conjugate by removing the final -ru and adding the necessary ending, the irregular verbs do their own thing, and the godan verb conjugate based on their ending sound (but there are some patterns).
and realised that the method I describe here does not help specifically to determine what group a verb belongs to. However, following this method has helped me a lot to come up with the right conjugation for the verbs I learn, so it may help.
I would suggest you to reword your question title if the main concern is the one in your comment. The title suggests that your problem is with remembering the conjugations, rather than discerning what group a verb belongs to.
Every time you do your vocabulary review with Anki or your favourite tool, when a verb comes up (including する verbs), try not only to say the verb once in the dictionary form, but say the verb in all the conjugations you know so far. It seems daunting, but when you start doing this for every single verb you know, it gets easier to say the conjugations without thinking about it whenever you have to use the verb in context. This is my own experience.
I will give you an example of how I do it with flashcards:
1) I come across the following flashcard:
2) I click on "show answer" and I'm presented with the answer:
たべる, 食べる (一段【いちだん】)
3) At this moment regardless of whether I remembered the answer or not, I say out loud:
3) I click on "show me again" or "right answer" depending on whether I remembered the word at the step 2 or not.
I keep doing this for every verb, (including する verbs). I always say the conjugations in the same order for every verb.
Also note that in my flaschards, I write the type of verb (一段【いちだん】, 五段【ごだん】, する) on the front as a hint.