One for those that last decorated in the 70s/80s when halogens weren't the rage.
I've got a few incandescent R80 ES style eyeball light fittings in the ceiling and fitting replacement CFL and LED bulbs to them is not so cheap in bulk.
So, I've just hacked in a Golf Ball styled E14/SES 3W LED bulb from Poundland using a cheap ES/SES adaptor from Amazon ...
Wanway E27 to E14 Socket Converter,ES to SES (78 pence free delivery)
... using a discarded CD with an 25mm hole centre cut out (Q-Max metal punch) as a reflector / hider of nasty looking metal work up beyond the bulb. All looks better than in the photo when lit.
Had to bend the the CD carefully to get in and past the 85mm aperture opening. Expect to snap a few doing that (but AOL CDs are plentiful...)