Maureen, some good ideas given above.
If the company is a good one, then it is worth holding onto. I am not recommending it, but for some while I wanted to buy in to BG, but didn't have the where withall. When I did, the price was too high, but when they dropped, I dove in, only to see them drop another pound. They have since recovered, but the return is low, 1.41%. I am looking to the future (Mind you I should be more concerned with income, but never mind) and gas and moving it around is going to be the fuel in demand. My view.
Tobacco is going great guns at the moment, but with all this anti smoking, it will, almost inevitably fall, but the income is great, at the moment. I have two holdings, inherited, one from my father, and the other on the break up of a conglomerate.
Do not hold in CREST, as there will be account charges, if not now (and some do) then later. Get certificates. A higher charge initially, but then no charges. I watch the papers for tips and consider them.
I tend to wait for the dips in the market. A few years ago I had some money and then bought in, when I should have waited, I knew there was trouble on the horizon, but the market was rising. I did well on some shares, but had I waited for 6-9 months, I could have more than doubled the stocks purchased. I am still waiting for some of the stocks to hit break even, confident they will and then go on and do better, e. g. Lloyds.
Investing maxim, from the Intelligent Investor, be fearful when others are greedy (i.e. strongly rising market) and be greedy when others are fearful (falling market). The problem is timing.
Rather than doing little buys, accumulate and buy a bigger holding, you save on charges, and if a decent company and many do this, take shares in lieu of dividend. NEVER take the offer from a registrar to buy with the dividend the stock, most of the money will go to the registrar and charges, little to the stock. They are cowboys, guns for hire, muggers, expensive and highway robbers.