Here is a concrete and engaging alternative to the Moore Method that works for smaller class sizes. (I'm writing this because not everyone likes the somewhat confrontational style of Moore's original approach.)

1) Produce short online videos and posts them for the students to watch on demand. These don't have to be too polished at first, but can be refined. Really the biggest reason to produce them is to prevent students from thinking that the instructor somehow doesn't care and does not put in thought or time to teaching the class.

2) Use an overhead projector to project a nicely constructed problem set at the beginning of class. Tell the students they are allowed to collaborate on the problems in class, and their groups will be credited for solving the problems once they complete and explain their solution to the rest of the class, but that at the end of the week the problems that are left will be assigned as written homework. When students solve a problem and explain it, write the initials of the successful group of students next to the problem they have solved, to encourage their further work.

3) Assign the problems as written homework. Grade the homework and return it. Make clear in the syllabus that if the homework is not clear, or it seems like the student is cutting corners in some way...like copying from another student...or wikipedia...that you reserve the right to award a very low grade on the homework, and this low grade can be recovered by the student if they come to talk with you. Strong students appreciate not having to come and speak with you if they write things carefully, and sometimes will come and see you and get a lot out of the correction/oral exam. Very weak students will come to you several times, so you must remain encouraging every time...that is essential...but sometimes they will not be able to adequately correct things to repair the original shortcut. I find they get more help this way than otherwise, though.

The downside is, some students just won't even engage and do the homework. It's important to try to engage these students as soon as you can. Oh, and there are no exams and quizzes in the course. I have done this using Artin's Algebra 2nd edition for an intro course in Algebra, and it worked very well. For lower level courses, it might work to do the same thing but reserving the unsolved homework problems for the following week's quiz, but I haven't been able to do this effectively with a class size of around 30 students. The original method above works with a class of 15 or below.

Time consuming you say? I should reiterate that grading well-written homework takes little time since it is well-written, and spotting garbage is very quick. I argue that you spend about the same amount of time delivering "oral exams" than you would staring at gibberish and trying to find ways to award points...which to me seems like a very silly practice if you can speak with someone to figure out where they are confused about something. Also, it can take around 15 minutes to make a 15 minute video that roughly presents a proof so students can watch it and fight with it. If you are not producing your own problem script for the course, it seems to me that there is less prep time and grading time for this method, and far more time interacting with students...which takes a lot of energy, indeed, but is more effective in the long run.