Suggestions

Do you own two lights? Consider positioning one or both at angles to simulate morning and afternoon light. The standard and accepted practice of positioning lights directly above plants is inefficient without training , scrog etc. Why? Because ‘noon’ is only a very brief period in plants’ daily light intake. They get most of their light at angles, that penetrate to branches better than from above. Plants lit at angles grow bushy and squat without training, and sometimes without topping! I know it’s a head shaker cuz I’m one of the few doing it, and I don’t grow too much, but it works. And you don’t have to!! Forget training and nets. Waste of time. See my side lighting pics @growdoctordc on Insta. Most recently video of an untopped Dutch Dragon that remained short and is well into flower. She’s a beauty to behold. Enjoy growing and your harvests!

What Athos is saying, works for photos.. However, don't repot autos.. Start with the pot size you want to finish with, especially if you're not used to repotting. And then be careful about overwatering. - Get some free soil through a recycling facility that deals with compost.. At least were I live, they just throw it out for people to pick up no charge, when it's done. -Find a farmer, and ask if you can clean the chicken coop, - Mix the chicken shit with the compost. 15 liter pot of that, should be able to take an autoflower through to harvest with no additives. Good soil is really the only thing that'll give a better yield, without adding or buying anything. A good lamp, is what you should really be looking at.. Doesn't matter what you do, if your plants don't have the energy to process the nutrients from the soil, and energy is what the lamp provides.

Use a super soil! A proper sized pot with super soil should hold enough “additives” without needing extra. Autos have a shorter life and if the pot is big enough with good soil, you will be all good! I used indacanja soil with worm castings—- it’s cheaper than fox farms and seems to be doing the trick!

Additives do not increase yield. When you force feed pigs, they get fat, when you force feed plants, they get burned or killed. Here are the things that are much more important: 1. Use a pot the right size. Using an 8 gal pot for a seedling will make you over water. You need to start small and learn to transplant. Start with party cups or 1 liter / quart pots. This will also promote a better root zone, which will help with yield. 2. Each time you transplant grow 4 times your current size (party cups to half a gallon; quart to gallon), more or less, but avoid jumping form party cups to 3 gallon. 3. Over watering is the number 1 enemy, too much water will prevent the roots from taking oxygen, literally making them drown, which will slow growth down to a crawl. An over watered seedling in a 3 gallon pot can take weeks to grow while waiting for all that water to evaporate (been there, done that). 4. Learn to train, the idea is to get a flat canopy where every bud is at the same height. 5. Keep the temperature in the right range. Temps above 23°C (73°F) will make the growth explode; below that the growth rate is slowed down. 6. Keeping humidity in the correct range for each stage helps too (harder to do). 7. Only feed when the plant needs it. When in doubt, don't feed and wait for the first signs of nutrient deficiency to show. A deficiency can be corrected in a matter of days, a nutrient burn can screw the yield or even kill the plant.

Bigger pots possibly? low stress training would help yield.

none that are that "effective" some strains might benefit little more from it then others.. But light and co2 are the easiest ways to increase yield.

Good light, good airflow, proper training, proper watering schedule... Other than training, keeping everything else optimal costs money 🤷‍♂️🏻