You can do a joint deal with agents where you only pay the one that finds you the buyer. A lot of agents are reluctant to mention it, but most of the houses on RIghtmove near me are on with at least one agent, one is on with five. We didn't realise until we were told by a rival agent.
The real work of the estate agent is after the offer so make sure you choose ones that are active and aggressive. Our sellers solicitors are like attack dogs, they phone every few days to check the progress of the sale and are also chivvying along the seller and her solicitor. Ours have been the same to our buyer, we received an offer on the 2nd Jan, his mortgage has been arranged, surveys and searches done and all questions from all three sides have been answered within 24 hours. It has been fantastic.
Photos are important, some statistics that most people only look at the first three on RM before deciding to click through further. We were on with one agent who put our dated and stained kitchen on as the first picture , and left off the garage/parking which was the major selling point. Parking is terrible in our area and garages are like hens teeth, he also left it off the particulars completely! We were very glad of the 14 day cancellation period and went with another agent. The man who bought our house saw it had gone on the market at first and dismissed it until he saw the garage on the second set of particulars. That's what he was looking for and he didn't even consider our house until he saw the garage as the second picture on RM.
We have sold now but once we were on the market we had 10+ calls from other agents, four letters and one agent knocking on the door unannounced. The housing market is quiet in my area and they were all desperate for our business. Lots of room for negotiation on fees!
Tons of our stuff is in boxes in the roof, this made cleaning easier before viewings and made our house look very uncluttered. Make sure you and your agent (if they are doing viewings) know about your house, when extensions were done, broadband speed etc. Some viewers have a LOt of questions and it's better to be prepared.
Start digging out any paperwork, building completion certificates, guarantees, manuals for anything you might leave behind etc. It will save time in the long run, especially if you need to get new copies of certificates. Get the boiler serviced if you can. When you get viewings make sure you put the boiler on so the house is warm and welcoming and they can see it's working. If you have road noise or noisy neighbours then quiet music can help.
In my area people avoid online agents and they have a bad reputation. This is obviously not the case for all areas, but I've noticed that only the really hard to sell houses are on with online agents, often at overinflated prices.
Good luck