It is better to search for files, rather than using Sig2Dat hashes/quicklinks. If you do a search, you can see if the file is widely available or not. Also you start with sources to download from.
Sig2Dat hashes/quicklinks are still very usefull. You can compare the sizes in the search results with the size of the Sig2Dat. Then it is easy to pick the correct file. Tip: click on the filesize column in the search results to sort on the results on filesize.
Start a search. A single search (no AutoSearchMore) is enough if the file is popular. For more rare files do a couple of manual 'search more'. Stop searching when you have 10 or more sources. The reason why you shouldn't search until you get a lot of results will follow shortly.
Now start the download.
After that continue searching for the same file. This time you can enable AutoSearchMore if you want. Search for another minute or less. Two minutes for rare files. Searching longer doesn't help much, trust me.
You will notice that the download speeds are much higher now.
But why didn't we initially search until we had hundreds of results? Well, only a maximum of 30 sources is stored in the .dat file when you start a download. But once the download is started, an additional 120 sources can be added (150 total). That's why we continued searching after starting the download.
Finding more sources for active downloads
If you have a couple of big downloads that are downloading at snail pace, then it can help to find additional sources. Tools like Speed Up are good for that purpose. But sometimes it can also help to use the powers of ASM to give your downloads a boost.
Go to the seach panel and search for the same file as the one that you want to try to give a boost. Turn AutoSearchMore on. Search for a minute or less.