Why don't you just focus on one fundamental at a time. I would regard non verbal communication and eye contact as two of the most difficult since they require a lot of practice.
I'm not confident to list all fundamentals, but I'd suggest buying Chase's book and reading that section (no I'm not affiliated with this site).
In the meantime a huge improvement can be had for little effort by:
- Buying new tighter fitting clothes (I recommend some jeans, some chinos, some shirts in an M if at all feasible, some boots or loafers or just shoes in interesting colours with matching belts, look up smart casual fashion online too, also a navy blazer is a great accessory and some scarves, however your style may be totally different than mine)
- Starting to lose weight/put in place a sustainable and healthy diet
- Starting at the gym/putting in place a sustainable fitness & muscle building routine
- Buying jewellery (I recommend some rings and a watch and a titanium curb link chain, order them online, I go for all silver tone since its neutral but gold may suit your skin tone better)
- Buying cologne (get one for daywear in a light foresty or herbal scent and one for nightwear in a patchouli or musky kinda scent, this will be fucking expensive unfortunately)
- Having an edgy haircut and getting some good gel or wax based on salon recommendation
- Buying a stubble trimmer and using it to maintain 2~3mm of stubble, or if your facial hair is darker than mine maybe go for the soul patch and chinstrap recommended by Chase
- POSTURE POSTURE POSTURE -- shoulders back, visualizing a hook under your sternum
- Practicing moving slowly yet taking the longest stride you possibly can, let your upper body move a bit while walking so you can feel that M size shirt moving side to side slightly against your chest
- Practicing not leaning in when talking to people, also I'm told it's vital to maintain your posture (etc) during conversation (etc) though I find this difficult & need to work on it
Is that enough to get you started?
cheers, Ray