If you really want to invest with excess funds,

just do spot trading seriously, don't touch leverage,

if you have ideas but not much capital,

develop a trading plan, don't trade against the trend,

if you're right, hold on, if you're wrong, cut losses, don't hold onto losing positions, don't get liquidated……

withdraw profits when you've made some capital, similarly, when you've accumulated enough, withdraw it,

don't get impulsive, don't stare at ultra-short trades all day…