Making a live USB with persistent storage

I'm trying to make a Ubuntu live USB, but I have run into some problems:

1. Used LiveUSB install on my Lubuntu laptop. Breaks USB drive until reformatted, does not boot.


2. Used Startup Disk Creator on Lubuntu. Makes bootable drive, but not persistant storage


3. Used UNetBootin on Lubuntu, puts Ubuntu on USB stick but does not make it bootable


4. Tried to use Universal USB Installer with WINE, but it didn't work. The first time it could only see the floppy disk drive not the USB, the next time it threw an NSIS error.


5. Tried to use Universal USB Installer on Windows, but it needed admin permissions

I have a laptop with Lubuntu installed* (that I have the sudo password for), a Windows 8 desktop without administrator permissions and a 32GB sandisk USB stick. Is there anything else I can do to get it to work?

*IBM T-42 Thinkpad with 1GB ram and an intel Centrio mobile processor that I had to force PAE to get Lubuntu to install if it is relevant.

As requested:
sudo lsblk -f

NAME   FSTYPE  LABEL                    MOUNTPOINT
sdb    iso9660 Ubuntu 16.04.2 LTS amd64 2017-02-15-21-44-13-00               
├─sdb2 vfat    Ubuntu 16.04.2 LTS amd64 E561-C446                            
└─sdb1 iso9660 Ubuntu 16.04.2 LTS amd64 2017-02-15-21-44-13-00               
sr0                                                                   
fd0                                                                   

sda                                                                   
├─sda5 swap                             d571c534-8cb6-4e61-889c-6289f5a33421 [SWAP]
├─sda1 ntfs                             F8E0DED8E0DE9BE6                     
└─sda6 ext4                             b14a062d-7884-494c-99fe-ddfe5bd5f4b4 /


sudo lsblk -m

NAME    SIZE OWNER GROUP MODE
sdb    28.7G root  disk  brw-rw----

├─sdb2  2.4M root  disk  brw-rw----
└─sdb1  1.5G root  disk  brw-rw----
sr0    1024M root  cdrom brw-rw----
fd0       4K root  disk  brw-rw----
sda    37.3G root  disk  brw-rw----
├─sda5 1022M root  disk  brw-rw----
├─sda1   14G root  disk  brw-rw----
└─sda6 22.3G root  disk  brw-rw----