Can people CBT themselves, if so are there any simple techniques and strategies that could be used.
As the above poster mentioned, CBT is a recognition of unhelpful or destructive patterns of thinking. And thus, though it may be aided by a professional, it is largely 'performed' by means of the self.
That being said, the utilization of CBT techniques without guidance from a trained professional may or may not be beneficial, depending on the person. Without professional guidance, it is difficult to know where to look for information, and to know what sort of information is reliable. Furthermore, it can be difficult to stick to a behavioral routine, or to learn for oneself what to believe and what not to believe. In fact, evidence has occasionally shown that professionally-guided self-help is the only significant means of self-help, in terms of beneficial effect. 
On the other hand, other studies have shown that self-help CBT is more effective than TAU (treatment as usual) in the long run.  Though I think it is worth mentioning that participants in these trials were given clinically approved CBT manuals, as well as a regime to follow.
Therefore, it may be best to view CBT like one may view taking medication. If you are relying on anecdotal evidence or advice from non-professionals, you may be setting yourself up for failure in the long run (or even damaging yourself further). On the other hand, if you were to consult a trained professional for advice and then follow that advice, then you may have better luck. However, I am not sure if this constitutes as 'self-CBT' in the way that you are describing.
 Gellatly, Judith; Bower, Peter; Hennessy, SUE; Richards, David; Gilbody, Simon; Lovell, Karina (2007). "What makes self-help interventions effective in the management of depressive symptoms? Meta-analysis and meta-regression". Psychological Medicine 37 (9): 1217–28.
 Williams, Christopher; Wilson, Philip; Morrison, Jill; McMahon, Alex; Andrew, Walker; Allan, Lesley; McConnachie, Alex; McNeill, Yvonne et al. (2013). Andersson, Gerhard, ed. "Guided Self-Help Cognitive Behavioural Therapy for Depression in Primary Care: A Randomised Controlled Trial"