Also agree with everyone, if it has become an issue suddenly, something may be failing.
If you dont have a return line installed, there is a method for hot starting. Open your throttle (fully open), close the mixture. Hit your starter. Keep your right hand on the mixture lever and soon as the engine starts, reduce the throttle to idle while simutaniosly adjusting the mixture to full open, or as required. Works very well with Lycoming turbo engine which are notorious for hot start issues.