So I’ve finally got Gmail’s Insert Files using Drive feature, which lets you attach files from your Google Drive into mails. Drive gives you 5GB of cloud storage for free, so now you can attach files with size up to 5GB. Earlier the maximum size of an attachment was 25MB. To check if you’ve got the feature by now, click on Compose and see if there’s a Drive icon in the toolbar.
This is much easier than uploading to somewhere else, like Dropbox, and emailing the link, since you can do everything within Gmail. Still, I’m in favor of Dropbox for cloud storage. Drive is just for attachments and Google Docs.