Struggling to find a method

Hello! I grew up with a mom who only ever used cast iron. Hers never stick and always are perfect. I have tried seasoning my cast iron skillets to fail each time. Mine are always sticky afterwards or have spots that are sticky and never non stick. I asked my mom how she does them and she said after greasing hers up she puts them in the oven at a lower temp for an hour. However everyone on here always says cook them on a high temp. Confused! Advice, or suggestions would be great! Thanks