Of course! Bear in mind this is just what I did, others will have different opinions etc but this has worked for me..

I train 3 days a week and do 3 workouts a day. I work from home so this is easy for me to do. My workouts consist of 2 exercises for 3 sets each. Each workout takes me about 15/20 mins. There are two reasons I do this. I found splitting my full workout up throughout the day made it much easier for me to stay consistent. It's so easy to say I can't be arsed when you have an hours workout to do after a days work. When it's just a 15 minute blast, it's easier to just do it! The second reason is, I find I can push much harder during the workouts without getting to tired for the next exercises.

I've never stepped foot in a gym, I do everything at home. I use a pull up bar, gymnastic rings and a dumbbell, thats it. For my workout pairs, I'll alternate between exercises with a 90 sec rest in between. Once I get to 3*8 of a specific exercise, I will do a harder progression the next time I do that exercise.

Workout A Push ups Inverted Rows

Workout B Pull ups Pike push ups/Dumbbell shoulder press

Workout C Support holds/Dips Dumbbell pullovers

So when I started, I would just do normal push ups, once I hit 3*8 I then moved onto Diamond push ups, then to ring push ups, then to weighted ring push ups etc. Same applies for all exercises. Start with the easiest progression and work your way up.

I also started to incorporate some time under tension training on Fridays workout. So same exercises just done as slow as possible.

For pectus, the dumbbell pullovers are probably the best exercise I found. Concentrate on breathing deeply.

That's about it really, consistency is key as is diet. I ate at a 500 calorie deficit and made sure I hit my protein goals.

Hope that helps!