i already do forward and reverse bridges it helped my strength, i have alot of strength in my neck, but want thinckess
You simply have to put on overall quality weight through a proper diet, and a properly constructed full-body routine.
And, simply keep worken' it.
And, this simply will take some time. One can manipulate their training/diet, and attempt to optimize recoverability (messing with days of rest, and types of food eaten), etc, but building muscle simply takes time, and people "generally" have a misconception on how long (this time) means in the general sense.
Let's face it. For "most" people (understanding genetic exceptions) their body has a greater efficient capacity to put on fat than build muscle tissue, and right here is the problem, quite simply.
The natural body builders you see that are legit (legit meaning no marketing manipulation bull-****) appear this way through several YEARS of work, dedication and persistence to their chosen fitness goal.
Gots to put the work in. Fall down when making mistakes, and get up. Fix it, repair it, and repeat for the win.
And, some who embark on fitness goals, simply make it confusing/difficult than it really is in the basic sense of the definition.
IMO, Leckbass, you need to stop focusing on specific body parts (assuming you have been training for a very short while, and no imbalances), and focus more on:
1. Education.
2. Diet.
3. Constructing a proper weight routine--focusing on progressive overload.
4. Give it time to work.
5. And, what you want will follow.
Best wishes
Chillen