When I started playing RPGs, I made characters with high intelligence and problem-solving skills. As an engineer, these kinds of characters were similar to myself in real life and suited my natural play style.
As I grew more confident with roleplaying, I started playing characters with high charisma and persuasive skills. I have somewhat of a 'natural-leader' type personality where I like to take the lead on discussion and decision-making. These characters allowed me to explore that.
Eventually, I combined these skills and became the DM where I can flex all my problem-solving, discussion-driving, wannabe-leader skills without dominating the party. This has been great, and I've learned a lot and broadened my roleplaying skills significantly while doing it.
When the opportunity to return to playing came up, I created several characters that have a more 'follower'-type personality - not unintelligent or uncharismatic, but more meek and less likely to take the lead. I did this to try to roleplay outside my comfort zone (also playing my first female PC) and to try to curb my ability to lead the party.
These new characters don't come naturally to me. I have to actively force myself to 'sit on my hands' and contribute less than I naturally would. It's not that I don't have fun playing them - more that I struggle to actually play them the way I wanted to. Often I find myself deep in a convoluted strategy discussion or manipulating an NPC when I remember that it is totally out of character for the PC I am playing.
Additionally, as a long-time DM I have by far the best rules and system knowledge at the table. Often I can spot flaws and errors in other players' strategies that my character would not. I struggle to go along with the "sub-optimal" strategy even when it is absolutely what my character would do.
This question has some cross-over with this one on creating characters different to myself; however, I don't have a problem creating the character. I also don't really have a problem with playing them as a DM. I am asking for techniques from people who have struggled with similar issues as a player.
How can I better roleplay a meek character when I have a leader-type personality?
One of the characters I am playing is a rogue with a Folk Hero background. I wrote in her backstory that she tried to start a revolution to help her hometown; it ended up with a massacre when the Lord's army arrived. Since then, she has sworn off making serious decisions and likes to attach herself to another character who will stop her from making another terrible mistake.
In one session, we had a serious and complex political situation to deal with. Normally, this would be my area of expertise, and I took to it without thinking; I stormed into a council meeting and strong armed a few NPCs with my force of personality, I even managed to negotiate a truce between a Holy Order of Paladins and the Undead they came to slay. After the session, I realised that was totally out of character and wished I'd played it differently.