Use a prepaid no name Web ip tether if you absolutely have to use a computer. The more you have your name linked to your isp, the more you are linked to the data you transmit.
Encrypt whole device from cmos on a computer or from boot on a mobile device.
Encrypt all email with pgp. Share your keys ONLY over a non related mode.
On a mobile device , Use an ipbased texting method over the phones native MMS protocol. IP based texting gives you the advantage of changing accounts periodically vs having to change your phone.
Use a dual SIM, one for voice and one for data both burner.
Any browsing to websites, signing up etc use something simple like orbot.
In most cases convictions happen only because incriminating data was available IN PLAIN SIGHT, so hide your apps, from plain sight. It's not a sure shot but it's better than someone picking up your phone and finding stuff on it, with OR without a password.
Try to make all device storage to your SD card and with some research you can put your device cache on a removable SD card as well.
On a computer use a non writeable cache based interface like knoppix over windows.
Preferably keep your computer use to the bare minimum.
If a company is openly advertising a security solution and promises to keep your data away from LE needless to say it's common sense that they are probably going to be top on the DHS radar.
If you want to chat, till date , i still think good old IIRC dinosaur is the safest and most anonymous. May not be cool, but cool gets you caught.
If you are REALLY serious about security figure out how to ghost your ip (not the shitty ip masking solutions like hidemyass etc) and enforce that everyone you are in communication with uses pgp, blowfish and aes.
Remember you are only one side of the security bracket, it doesn't help your safety if the person you are dealing with is an absolute idiot and disregards security. The road goes both ways.


Bottom line, security is not about convenience , security is a bout safety. It's worth the long road