Forming an entity separates your personal assets from the business. That separation depends on treating the company as genuinely separate.
Mixing personal and company funds, skipping member or board consents, not keeping records, and undercapitalizing the entity are the facts a plaintiff points to when arguing that the corporate veil should be pierced.
The maintenance is unglamorous and cheap: a separate account, minutes for real decisions, signing in the company's name rather than your own. It is worth far more than it costs on the day somebody sues.