It’s been a while since the SharePoint 2010 Service Pack 1 has been released and if you want to install SharePoint with all updates applied it can take some time. Meanwhile you need to install SharePoint 2010 RTM, Service Pack 1 for SharePoint 2010 and some Cumulative Update like June or August.
You can enhance the process and save time if you create a slipstream copy.
SharePoint media you need
In order to create the copy you need to download:
- SharePoint 2010 RTM
- Service Pack 1 for SharePoint 2010
Create the SharePoint 2010 slipstream copy
If you extract the SharePoint 2010 RTM install executable you have a folder structure with an updates folder:

Next you can extract the Service Pack 1 installer. You can see the possible operations while executing the file with the following parameter:
officeserver2010sp1-kb2460045-x64-fullfile-en-us.exe /?

The parameter opens a pop up with the following instructions...
The /extract:path is the interesting here:

You can extract the install media by using the extract:path parameter:
officeserver2010sp1-kb2460045-x64-fullfile-en-us.exe /extract:path

SharePoint Server 2010 and SharePoint Foundation 2010
If you compare the extracted files from the SharePoint Foundation 2010 Service Pack 1 and the equal files from the SharePoint Server 2010 Service Pack 1 you can see that there is no difference:

It looks like there is no need to first extract SharePoint Foundation 2010 SP1 into the folder an later the SP1 for SharePoint Server 2010.
When it comes to the Cumulative Update I don’t know yet if it works to extract them… I will check that later.