Top lawyers spot improper joinder by promptly auditing the complaint and facts against applicable joinder and jurisdictional rules (transactional nexus, common questions, and diversity/fraudulent-joinder tests), looking for misaligned parties or claims and any tactical motive to defeat jurisdiction; they then gather supporting evidence and precedent, try a meet-and-confer to narrow or amend pleadings, and—if no agreement—move quickly to sever, dismiss, or remand with focused briefing that highlights prejudice and procedural defects. In parallel they ask the court for case-management relief (bifurcation, limited discovery, protective orders), tailor discovery to avoid fishing expeditions, preserve the record for appeal, and consider cost-shifting or sanctions where appropriate; throughout, they rely on checklists, jurisdiction-specific authorities, clear client communication, and pragmatic settlement or narrowing strategies to keep the litigation efficient and protect their client’s rights.