That's why agents give more attention to the most attractive and best-maintained homes on the market. Your home needs to be in tip-top condition. If you can't afford to get your home in top condition, you should at least keep the home clean and clear a path through your clutter. Buyers can imagine what a garage looks like, but they can't imagine what a bedroom or living room looks like when stuff is stacked to the ceiling. Make your home available for showings.
Access includes marketing strategies as well as showings.
Others, if the wind is blowing the wrong way, forget it. If you want to sell your home, make it available. As does a low commission, an inaccessible home turns off buyers' agents, as well as the listing agent. Communicate with your agent. Agents do not like being left in the dark any more than sellers do.