Adding a link to this page from your iPhone will allow you to create an invisible icon that can be used to reposition your home screen's icons exactly how your desire. Follow the steps outlined below for each blank you require.
1) Tap the Action button on the toolbar.
2) Tap the Add to Home Screen button from the Share Sheet.
3) Tap the Add button from the Share Sheet. Do not touch the title field, it will be pre-filled with an invisible character so that nothing shows below the icon.
4) Repeat for however many blanks you want.
5) Now whenever you put your icons into Wiggle Mode you'll be able to positing these invisible blanks wherever you want them. (Shown below against a contrasting background since, well, they are invisible otherwise).