Don't remove the ashes, and take out the grates if you have them. Let a few inches of ashes build up, and let the coals build up in the ashes. Years ago we heard about people banking the fire before they went to bed. I believe that was putting some ashes up over the coals so they would be there in the morning when a new supply of wood was added. You don't say what species of wood you are burning, but there are some (red oak, white oak) that are better than others (aspen, pine, fir, basswood, etc.) that are fast burning and a whole lot in between. The heavier the wood the better. The drier the wood the better. Once you have good layer of hot coals, then some wet wood (air dried at least a year) can be added to sustain the fire. Keep the coals the back, and control the air that is getting to the fire. More air, the hotter the fire, and the faster the wood will burn. Grates are perfect for burning wood fast. Take them out or let the ashes build up so there is very little space beneath them. They are only good for starting a fire if one uses a big wad of crumpled up newspapers, and want a way to get them under the wood.
My experience with fireplaces is I kept mine going in the 70's from the middle of Sept. to the beginning of May for several winters without (except for very few times) it going out, and that meant stretches of 8-9 hours with no wood added. I burn only red and white oak, dried under cover for a minimum of 3 years. Keep an eye on the condition of the chimney. It will clean itself via a chimney fire if you don't clean it first. The chimney fire is not the preferred way. I hope this helps some. It's an art that will take some time to learn, but its great to have the fireplace going.
