Open the Messaging app (set it as your default messaging app, if necessary), then tap the New message icon (at the top right of the screen).
Enter the recipient(s) in the To box.
Tap the Contacts icon (to the right of the To box) to select one or more entries from your Contacts list.
Enter a name, number, or email address, then select a suggestion from your Contacts list (displayed below the To box).
Enter a number or email address manually.
Tap the text field, then enter your message.
Tap the Menu icon (at the upper-right corner of the screen) > Add subject to add a message subject.
The subject text appears above the body text in bold letters.
Tap the Attachment icon to open a dialog box where you can choose the type of media file to attach to the message.
Tap Picture to select a picture from your Gallery.
Tap Take photo to take a photo and attach it.
Tap Video to select a video from your Gallery
Tap Record video to record a video and attach it.
Tap Audio to select an audio file.
Tap Record voice to record an audio message and attach it.
Tap Location to select a map location to send.
Tap Contact to select either vCard or text to attach.
Tap Schedule to select an event to send.
Tap Slide to assemble up to 10 items (photos, videos, audio and/or text) to attach to your message.
To delete an attachment, simply tap the Delete icon on the attached file.
Tap the Send MMS button (on the right side of the screen) to send the message.